Full opinion text
REENA RAGGI, Circuit Judge: United States citizen Hassan Abu-Jihaad, whose birth name is Paul Raphael Hall, appeals from a judgment of conviction entered in the United States District Court for the District of Connecticut (Mark R. Kravitz, Judge) on April 3, 2009, after a jury found him guilty of having communicated national defense information, specifically, the anticipated movements of a United States Navy battlegroup being deployed to the Persian Gulf, to unauthorized persons in violation of 18 U.S.C. § 793(d). Presently serving a ten-year prison term for that crime, Abu-Jihaad contends that (1) inculpatory evidence obtained pursuant to the Foreign Intelligence Surveillance Act (“FISA”), 50 U.S.C. § 1801 et seq., should have been suppressed because (a) that statute is unconstitutional and (b) in any event, was not complied with in this case; (2) erroneous evidentiary rulings deprived him of a fair trial; (3) the trial evidence was insufficient to support conviction; and (4) the district court abused its discretion in entering protective orders pursuant to the Classified Information Procedures Act (“CIPA”), 18 U.S.C. app. 3, §§ 1-16. We identify no merit in any of these arguments and, accordingly, we affirm the judgment of conviction. I. Background In 1997, defendant Paul Raphael Hall changed his name to “Hassan Abu-Jihaad,” the surname of which translates to “Father of Jihad.” This curious choice appears not to have raised any concern in the United States Navy when, in January 1998, Abu-Jihaad enlisted. Indeed, over the course of Abu-Jihaad’s military service, from 1998-2002, the Navy would clear defendant to receive classified national defense information. The Navy’s trust was misplaced. As the jury found, sometime in early 2001, Abu-Jihaad leaked classified information about the movements of Navy ships destined for the Persian Gulf to unauthorized persons supportive of jihad. Because Abu-Jihaad challenges the sufficiency of the evidence supporting the jury verdict, we discuss that evidence in some detail. A. Discovery of the Classified Information in a London Search The first link in the chain of circumstantial evidence proving Abu-Jihaad’s guilt was discovered in London where, on December 2, 2003, British authorities conducted searches of various locations associated with Babar Ahmad, an information technologist at London’s Imperial College with ties to Azzam Publications. 1. Azzam Publications’ Support for Jihad London-based Azzam Publications (“Azzam”) was an organization that in 2001 maintained a number of websites that glorified martyrdom in the name of jihad and the violent exploits of mujahideen around the world. See United States v. Abu-Jihaad, 600 F.Supp.2d 362, 366 (D.Conn.2009) (reviewing trial evidence in denying post-verdict motions for judgment of acquittal or new trial). Its name paid tribute to Sheikh Abdullah Azzam, a leader in urging the revival of violent jihad in the twentieth century. In addition to marketing jihadist audio and video recordings on its websites, Azzam offered English translations of books written by Sheikh Azzam. It also provided access to the 1996 fatwa issued by Osama bin Laden, entitled a “Declaration of War Against the Americans Occupying the Land of the Two Holy Places,” which charged Muslims to take up arms against the United States to rid the Arabian Peninsula of “infidels.” Id. at 367. It solicited assistance for jihadist groups, for example, requesting that readers aid the Taliban “by sending money or gas masks, or traveling to Afghanistan to provide battlefield medical services” in anticipation of an offense by American and Russian forces in retaliation for the October 2000 attack on the U.S.S. Cole. Id. at 366-67. One of Azzam’s most popular postings instructed Muslims living in Western countries as to how they, too, could train as mujahideen. 2. The December 2, 2008 Discovery of the Battlegroup Document In the course of searching Babar Ahmad’s bedroom on December 2, British authorities discovered a computer disk containing materials related to Azzam. Of particular significance to this case was a file denominated “letter.doc,” which contained a three-page unsigned document describing the anticipated spring 2001 deployment of ten U.S. Navy ships carrying approximately 15,000 sailors and marines from the Pacific coast of the United States to the Persian Gulf (“the Battlegroup Document”). Id. at 367. The significance of the Battlegroup Document is best illustrated by quoting it directly. The first page states as follows: In the coming days the United States will be deploying a large naval/marine force to the Middle East. This will be a two group force: the Battle Group (BG) and the Amphibious Readiness Group (ARG) — these groups will be replacing the already deployed groups in the gulf. The BG mission is to hold up the sanctions against Iraq, e.g. patrolling the No-Fly Zone, carry out Maritime Interception Operations (MIO) or launch strikes. There is a possibility that the ships and submarines that are capable will carry out a strike against Afghanistan. Main targets: Usama and the Mujahideen, Taliban, etc. A two star admiral, COMCRUDESRON 1 (his title), a high ranking officer of the BG said that “there will be certain ships of this BG sitting off the coast of Pakistan with ‘launch pads.’ ” Most of the ships that are part of the BG will deploy on March 15 2001 leaving their home ports out of California and Washington State. They will meet up with the other ships that are part of the BG which are stationed in Hawaii. Their first port stop is Hawaii on March 20 2001, where some ships will load Tomahawk D missiles. The same missies used on Afganistán and Sudan. It has a warhead and 166 [mm?] fragment bomblets. Then the whole BG will head towards Austrailia. The main ship with high ranking officials will be at Sydney on April 6 2001, other ships — Melbourne, Perth, Bunbary etc. The BG will be going through the straits of Hormuz on the April 29 2001 at night, cutting off certain “infocoms” and “Emcoms” to divert their enemies on how many ships are actually coming through. This will be a night time set-up. Gov’t Ex. 1. Immediately beneath this text is a diagram showing a two-column formation in which identified ships in the battlegroup, including the aircraft carrier U.S.S. Constellation and the destroyer U.S.S. Benfold — on which Abu-Jihaad served as a signalman — were expected to enter the Strait of Hormuz. Following the diagram are brief descriptions of the capabilities of each ship. For example, with respect to the battlegroup ships, the document states: 1. USS Constellation (CV 64) Kitty Hawk Class carrier Personnel: 5,500 to 6,000 Special team: onboard Explosive Ordnance Disposal team (EOD) Mission: No-fly zone, patrol, etc. 2. USS Chosin (CG-65) Ticonderoga class Personnel: 350 to 400 Specialisation: anti-air warfare Plus carrier escort all these ships 3. Kinkaid (DD965) Sprvance class3 Personnel: 300-350 Specialisation: MIO etc 4. USS Benfold (DDG-65) Arleigh Burke class Personnel: 300 Multi-capable ship 7. USS Rainer (AOE-7) Personnel: 400 to 500 Ammo and fuel replenishing ship for the BG. Id. With respect to the Amphibious Readiness Group, the document reveals that three ships were expected to deploy “out of homeport San Diego, March 14 2001” with a port visit in South-East Asia, specifically, in Thailand and Singapore, before heading to the Middle East. Id. Among the ships described is the following: 1. USS BOXER (LHD9) com ship, Wasp class Personnel: 1,500 sailors, 2,500 marines; high ranging officials abroad; also special forces, Navy Seals and Marines Special Unit Reconnaissance ships carries lots of helos [helicopters?] all kinds. Id. The document concludes by identifying the battlegroup’s vulnerabilities, highlighting its operation schedule in the Persian Gulf, and then exhorting the recipient to destroy the communication: Weakness: They have nothing to stop a small craft with RPG etc, except their Seals’ stinger missiles. Deploy ops in Gulf 29 April — 04 October. 29th APRIL is more likely the day through the Straits. For the whole of March is tax free — a moral booster. Many sailors do not like the Gulf. Please destroy message. Id. Based on forensic analysis of the totality of evidence obtained in the ensuing investigation, a federal agent testified at trial that the disk containing the Battlegroup Document appeared to have been created by British citizen Syed Talha Ahsan, an Azzam employee who handled product backlog. See United States v. Abu-Ji haad, 600 F.Supp.2d at 369. Further, although the Battlegroup Document was created on April 2, 2001, the diagram depicting the battlegroup’s formation was not embedded in the file until April 12, 2001, the date the document was last saved. See id. at 370. On that date, the author field in the document’s properties was changed from “S A Ahsan” to “Jon Greene.” Id Forensic analysis revealed that “wiping” software had been used to remove other material from the disk, but federal authorities were unable to recover that material. Id. In the course of their larger investigation, authorities would recover no other electronic data from any source revealing trace information pertaining to transmittal of the Battlegroup Document, research into United States naval forces generally or the Constellation battlegroup in particular, or any evidence relating to “Jon Greene.” B. Abu-Jihaad’s Transmittal of the Battlegroup Document To prove Abu-Jihaad’s transmittal of the Battlegroup Document (or the information contained therein) to persons at Azzam, the government relied on evidence showing: (1) defendant’s access to the information; (2) his communications with Azzam expressing support for jihad; and (3) his implicit admission in a 2006 recorded statement to having disclosed confidential national security information while in the Navy. 1. Defendant’s Access to the Transit Plan The 2001 deployment of the Constellation battlegroup from San Diego to the Middle East was executed pursuant to a Navy transit plan that went through many drafts beginning on September 29, 2000, and continuing through finalization on February 24, 2001. Each of these iterations highlighted the date April 29, 2001, when, just before midnight, the battle-group would cross the “change of operation control” (“CHOP”) point, ie., enter into the geographic region controlled by the United States Fifth Fleet. Only the final transit plan referenced a stop in Hawaii by a single vessel, the U.S.S. Benfold, to load ammunition. No version of the transit plan specified the date on which the battlegroup would pass through the Strait of Hormuz. Each iteration of the transit plan was classified “confidential,” which denotes “information, the unauthorized disclosure of which reasonably could be expected to cause damage to the national security that the original classification authority is able to identify or describe.” Exec. Order No. 12,958, § 1.3(3), 60 Fed.Reg. 19,825 (Apr. 17, 1995); see also United States v. Abu-Jihaad, 600 F.Supp.2d at 377 (noting Navy’s operational instructions stating that “precise current or future operational deployment, locations of surface combatant ships, and planned foreign port calls should be classified as ‘confidential’ until after deployment or the visit has been approved by the host government” (some internal quotation marks omitted)). Retired Rear Admiral David C. Hart, Jr., who commanded the Constellation battle-group during the time here at issue, explained that the Navy does not disclose anticipated ports of call because ships are particularly vulnerable in such locations. A similar concern counseled against disclosure of plans for ships to travel through areas where their maneuverability was limited, such as the Strait of Hormuz. Because of these concerns, even among persons assigned to ships in a battlegroup, only those with a “secret” clearance would be given access to a transit plan. Of 300 sailors on board the U.S.S. Benfold, Abu-Jihaad was one of 40 afforded such access by virtue of his status as a signalman who worked alongside quartermasters in the preparation of the ship’s navigational charts. He did not, however, have access to the Navy’s secure intranet for classified information (“SIPRnet”), which contained information even more sensitive to the national defense than that contained in the transit plan. Significantly, the Battle-group Document revealed no information for which SIPRnet clearance would have been required, thus limiting the likely source of the information it contained to persons with access only to the transit plan. 2. Abvr-Jihaad’s Communications with Azzam Even before United States officials received a copy of the seized Battlegroup Document from their British counterparts, federal agents, acting pursuant to court order, had searched various Azzam-affiliated electronic accounts and discovered therein eleven email exchanges in the time frame of August 21, 2000, to September 3, 2001, between Azzam and a United States sailor serving on the U.S.S. Benfold: the defendant Hassan Abu-Jihaad. Abu-Jihaad used both his personal and military email addresses in these communications. In its review of 23,000 Azzam emails, the government discovered only two correspondents with military email addresses: (1) a Navy Commander who commented angrily on Azzam’s support for jihad and (2) Abu-Jihaad. Moreover, Abu-Jihaad’s military email address was one of the few addresses saved in an Azzam email account address book. In his early emails with Azzam, Abu-Jihaad discussed purchases of various materials, including the videos Martyrs of Bosnia, Russian Hell 2000, Part I, and Chechnya from the Ashes (which included the feature Russian Hell 2000, Part II). In later emails, Abu-Jihaad revealed his identity and status as an active duty member of the Navy and his personal support for jihad, even when directed against the United States. In a July 2001 email sent from Abu-Jihaad’s personal email account to qoqaz@ assam.com — the email address to which Azzam’s websites directed readers to send their messages of support — defendant praised the “martyrdom operation against the uss cole” and the debilitating effect of that action on the United States (“Cole email”). Trial Tr. at 333-34; Gov’t Ex. 19. The text of the Cole email, which was retrieved only because it was embedded in Azzam’s reply, states as follows: i am a muslim station onboard a u.s. warship currently operating depolyed to the arabian gulf, it shall be noted before usama’s latest video was viewed by massive people all over the world, that psychological anxiety had already set in on america’s forces everywhere, all this is due to the martyrdom operation against the uss cole, since then every warship station either on the western or eastern shores of america who come to operate in the 5th fleet op area has to be given a force protect brief, well during the brief, i attended there was one thing that stuck out like thorns on a rose bush, i do not know who was the originator of this either top brass or an american poitician. well here is his/her statement: “america has Never faced an enemy with no borders, no government, no diplomats, nor a standing army that pledges allegiance to no state.” Allahu Akbar! Allahu Akbar! i give takbirs [praise to Allah] because i know deep down in my heart that the american enemies that this person has discribe is the Mujahideen Feesabilillah [holy warriors fighting in the cause of Allah], these brave men are the true champions and soldiers of Allah in this dunya [world], i understand fully that they are the men who have brong honor to this weak ummah [Islamic community] in the lands of jihad afghanistan, bosnia, Chechnya, etc. Alhamdulillah! [Praise to Allah!] With their only mission in life to make Allah’s name and laws supreme all over this world, i want to let it be known that i have been in the middle east for almost a total of 3 months, for these 3 months you can truly see the effects of this psychological warfare taking a toll on junior and high ranking officers, but after the latest video supporting Palestine, the top brass and american officials were running around like headless chickens very afraid, wondering if there is a possible threat, but this time the american population got wind of this and they came to know just how afraid the u.s. government is. thomas 1. friedman wrote an article in the new york times called: “what it takes to make the americans to turn tail, run.” this article was distributed on my ship and most of the sailors said it was so true about the american government, and they feel like they are working for a bunch of scary pussies.... a Brother serving a Kuffar [infidel] nation. Astaghfir’Allah [Forgiveness from Allah] .... Hassan United States v. Abu-Jihaad, 600 F.Supp.2d at 372-73 (emphasis and bracketed material added by district court). Abu-Jihaad’s Azzam correspondent replied in relevant part: You said it all, and all I can add is that the Kufar know that they cannot defeat the Mujahideen (the warriors of Allah). I trust that you are doing your best to make sure that the other brothers & sisters in uniform are reminded that their sole purpose of existence in this duniya [world] is purely to worship our Lord and Master, Allah (SWT) [praise being given to Allah], May Allah be with you & your brothers and sisters and keep you from all harm. Keep up with the Dawah [preaching Islam] and the psychlogical warefare. Id. at 373 (bracketed material added by district court). In the last of the eleven emails recovered by the government, Abu-Jihaad praised Azzam’s coverage of the Taliban in Afghanistan, but opined that the Taliban were too lenient in failing to execute foreign aid workers who converted Muslims to other faiths. None of Abu-Jihaad’s recovered emails referenced the Battlegroup Document or the information contained therein. 3. Abur-Jihaad’s 2006 Recorded Statements In 2006, by which time Abu-Jihaad had been out of the Navy for four years and was living in Phoenix, Arizona, Abu-Jihaad’s telephone conversations with his friend Derrick Shareef and a confidential informant were intercepted by a court-authorized wiretap. In excerpts of four calls from late 2006 that were played for the jury, Abu-Jihaad revealed his familiarity with Azzam’s websites, see Gov’t Ex. 141c, and his high degree of concern with “tapped” telephones, Gov’t Ex. 141e. Abu-Jihaad stated an intent to “secur[e] myself’ to avoid “handfing] myself to a Kafir [infidel].” Gov’t Ex. 141f. He cautioned those with whom he spoke not to refer to associates by their real names, see Gov’t Ex. 141g, and he frequently employed code, referring to jihad as “J” or “7,” e.g., Gov’t Ex. 141c, logistics as “L,” e.g., Gov’t Ex. 141g, martyrdom operations as “M.O.,” e.g., Gov’t Ex. 141f, and military intelligence as “meals,” e.g., Gov’t Ex. 141k. Thus, Abu-Jihaad’s references to a “cold meal” meant outdated intelligence, whereas a “fresh meal” or “hot meal” referred to current intelligence. Trial Tr. at 975-76. In a November 11, 2006 conversation, Abu-Jihaad stated that he no longer had current logistics information: “Now ‘L’ for me is like a cold meal. ‘Cuz it ain’t fresh.... If it ain’t fresh, it’s un-fresh and it, it’s un-beneficial to you — just put it that way.” Gov’t Ex. 141g. He repeated this point in a subsequent conversation with Shareef and the confidential informant the same day: ABU-JIHAAD: And I said, and I’ll say it again, with whatever I can give you, that’s beneficial, I’ll give it to you. But whatever’s cold turkey, if it’s cold turkey, I can’t give it to you. CW: Ak ... ABU-JIHAAD: ‘Cuz that means that, if it’s cold turkey — I’m talking about “L” you figure it out — ‘cuz then that means that, that’s just saying that, I haven’t been on that job, so I don’t— you know what I’m saying, I haven’t been there ... to see ... what the fresh meal is. SHAREEF: Okay. ABU-JIHAAD: You understand that? SHAREEF: Yeah. CW: Tell him, man I already got brothers ... ABU-JIHAAD: If I can’t, if I can’t give you the fresh meal — I ain’t been there in “X” amount of years. SHAREEF: Yeah, I — I understand what you’re saying. ABU-JIHAAD: See what I’m saying? Now if ... the Hispanic, if the Mexican, he just, was there a minute ago— he can give you a fresh meal. SHAREEF: Okay. ABU-JIHAAD: So you put that together. ABU-JIHAAD: If it’s — if it’s ... in those terms, he can give you a fresh meal ‘cuz, you know what I’m saying, he just finished his job, there, less than a month ago, or ... SHAREEF: Okay. ABU-JIHAAD: ... two. (LAUGHS). But I, I mean — in those terms and “L’s,” — I would be giving you a cold meal. CW: I understand. SHAREEF: Allrighty. ABU-JIHAAD: You got me? SHAREEF: Yeah, I got you. ABU-JIHAAD: Because, um — and then I can elaborate on that more if you want me to ... CW: No, no ... ABU-JIHAAD: ... to your face — not on the phone. I’m just saying ... if we ... you got me? SHAREEF: Yeah, man ... we good, we good. ABU-JIHAAD: A fresh meal and a cold meal. Gov’t Ex. 141h at 1-2. The informant testified that when Abu-Jihaad said he had not “been on that job,” the informant understood Abu-Jihaad to mean he was no longer in the Navy. By contrast, the informant understood the “Mexican” to be a reference to Miguel Colon, a man who had left the Marine Corps only recently in September 2006. Still later on November 11, 2006, Abu-Jihaad spoke with Colon about Shareef s wish to procure military intelligence: ABU-JIHAAD: [H]e wants a hot meal. You know what I’m saying? COLON: Yeah. ABU-JIHAAD: I don’t know how to get him no hot meal. I told him I, I ain’t been working uh, in, in, in the field of making meals and or, you know ... COLON: Yeah. ABU-JIHAAD: ... in a, in a long time. I’ve been out of that for, uh, over uh, quatro years you know. Gov’t Ex. 141k at 7. At trial, the government argued that, by explaining his present inability to provide military intelligence by reference to the fact that he had not been “working ... in the field of making meals” for four years, Abu-Jihaad was effectively admitting that he had leaked military intelligence while in the Navy. C. Conviction and Sentencing Based on the evidence summarized, on March 5, 2008, the jury found Abu-Jihaad guilty of both providing material support to terrorists in violation of 18 U.S.C. § 2389A and communicating national defense information to unauthorized persons in violation of 18 U.S.C. § 793(d). On March 4, 2009, the district court granted Abu-Jihaad’s motion for a judgment of acquittal as to the first count and denied the motion as to the second count. See United States v. Abu-Jihaad, 600 F.Supp.2d at 394, 402. The following month, on April 3, 2009, the district court sentenced Abu-Jihaad on the single count of conviction to the statutory maximum term of ten years’ imprisonment, to be followed by three years’ supervised release. This appeal followed. II. Discussion A. The FISA Challenge In securing Abu-Jihaad’s conviction, the prosecution relied on certain recorded evidence intercepted pursuant to court orders issued under the Foreign Intelligence Surveillance Act (“FISA”), 50 U.S.C. § 1801 et seq. Abu-Jihaad submits that the district court erred in refusing to suppress this evidence because (1) on its face, FISA violates the Fourth Amendment; and (2) in any event, the statute’s requirements were not satisfied in this case. We identify no merit in either argument. 1. FISA Is Constitutional on Its Face a. FISA’s General Operation Enacted in 1978, FISA permits the Chief Justice of the United States to designate eleven federal judges as the Foreign Intelligence Surveillance Court (“FISA Court”), see id. § 1803(a)(1), with jurisdiction to entertain ex parte executive applications for electronic surveillance “for the purpose of obtaining foreign intelligence information,” Id. § 1802(b). To issue a FISA warrant, a judge must find, inter alia, that there is probable cause to believe that the target of the surveillance is a “foreign power or an agent of a foreign power” and that the place or facilities to be surveilled are “being used, or ... about to be used, by a foreign power or an agent of a foreign power.” Id. § 1805(a)(2). Rulings by the FISA Court are subject to review by the Foreign Intelligence Surveillance Court of Review (“FISA Review Court”), which consists of three judges also designated by the Chief Justice. See id. § 1803(b). The FISA Review Court has convened only twice since the statute’s enactment: (1) when it heard and rejected a constitutional challenge to FISA not dissimilar to that pursued by Abu-Jihaad in this case, see In re Sealed Case, 310 F.3d 717 (FISA Ct. Rev.2002); and (2) when it heard and rejected an as-applied constitutional challenge to certain provisions of the Protect America Act of 2007 (“PAA”), Pub.L. No. 110-55, 121 Stat. 552, that permitted the executive to conduct warrant-less foreign intelligence surveillance on targets reasonably believed to be located outside the United States, see In re Directives Pursuant to Section 105B of the Foreign Intelligence Surveillance Act (In re FISA Section 105B Directives), 551 F.3d 1004 (FISA Ct. Rev.2008). b. The PATRIOT Act’s Amendment of FISA’s Purpose Certification Requirement As originally enacted, FISA required a high-ranking member of the executive branch to certify that “the purpose” for which a warrant was being sought was to obtain “foreign intelligence information.” 50 U.S.C. § 1804(a)(7)(B) (Supp. V 1981). Referencing this language in United States v. Duggan, 743 F.2d 59 (2d Cir.1984), we observed that “the requirement that foreign intelligence information be the primary objective of the surveillance is plain not only from the language of § 1802(b) but also from the requirements in § 1804 as to what the application must contain.” Id. at 77 (emphasis added). Duggan rejected a Fourth Amendment challenge to the procedures established by FISA for issuance of foreign intelligence surveillance warrants, see id. at 72-74, a decision we recently had occasion to reaffirm in United States v. Stewart, 590 F.3d 93 (2d Cir. 2009). In 2001, Congress amended FISA as part of the Uniting and Strengthening America by Providing Appropriate Tools Required to Intercept and Obstruct Terrorism Act (“PATRIOT Act”), Pub.L. No. 107-56, 115 Stat. 271 (2001). Among other things, Congress indicated that it did not, in fact, require foreign intelligence gathering to be the primary purpose of the requested surveillance to obtain a FISA warrant. Rather, upon satisfaction of all other FISA requirements, Congress authorized FISA Court judges to issue warrants upon executive certification that acquisition of foreign intelligence information is “a significant purpose” of the requested surveillance. See id. § 218, 115 Stat. at 291 (codified as amended at 50 U.S.C. § 1804(a)(6)(B)) (emphasis added). Because neither Duggan nor Stewart considered FISA’s constitutionality in light of the statute’s amendment by the PATRIOT Act, Abu-Jihaad submits that we must address the question of constitutionality yet again. Specifically, Abu-Jihaad submits that the primary purpose requirement is, in fact, essential to the constitutionality of FISA, lest the government misuse the statute to procure warrants for criminal investigations without demonstrating the probable cause essential to that latter purpose, ie., probable cause to believe “that an individual is committing, has committed, or is about to commit a particular offense” and that “particular communications concerning that offense will be obtained through” the surveillance. See 18 U.S.C. § 2518(3)(a)-(b) (stating probable cause required by Title III of the Omnibus Crime Control and Safe Streets Act of 1968, Pub.L. 90-351, 82 Stat. 197 (codified as amended at 18 U.S.C. §§ 2510-2522)). In support of his challenge, Abu-Jihaad cites Mayfield v. United States, 504 F.Supp.2d 1023 (D.Or.2007) (holding FISA in violation of Fourth Amendment). That district court decision, however, has now been vacated by the Ninth Circuit on standing grounds. See Mayfield v. United States, 599 F.3d 964, 973 (9th Cir.2010). Meanwhile, all other courts that have considered the issue, both before and after enactment of the PATRIOT Act, have rejected constitutional challenges to FISA. See United States v. Ning Wen, 477 F.3d 896, 898 (7th Cir.2007); United States v. Damrah, 412 F.3d 618, 625 (6th Cir.2005); In re Sealed Case, 310 F.3d at 742-46; United States v. Johnson, 952 F.2d 565, 573 (1st Cir.1991); United States v. Pelton, 835 F.2d 1067, 1075 (4th Cir.1987); United States v. Cavanagh, 807 F.2d 787, 790-92 (9th Cir.1987); United States v. Kashmiri, No. 09 Cr. 830 — 4, 2010 WL 4705159, at *3-5 (N.D.Ill. Nov.10, 2010); United States v. Warsame, 547 F.Supp.2d 982, 993 (D.Minn.2008); United States v. Mubayyid, 521 F.Supp.2d 125, 135-41 (D.Mass.2007); United States v. Holy Land Found. for Relief & Dev., No. 04 Cr. 240, 2007 WL 2011319, at *5-6 (N.D.Tex. July 11, 2007); United States v. Jayyousi, No. 04 Cr. 60001, 2007 WL 851278, at *1 (S.D.Fla. Mar.15, 2007); United States v. Benkahla, 437 F.Supp.2d 541, 554 (E.D.Va.2006); United States v. Marzook, 435 F.Supp.2d 778, 786 (N.D.Ill.2006); United States v. Nicholson, 955 F.Supp. 588, 590-91 (E.D.Va.1997); In re Kevork, 634 F.Supp. 1002, 1014 (C.D.Cal.1985); United States v. Falvey, 540 F.Supp. 1306, 1312 (E.D.N.Y.1982). We do the same here. As we discuss more fully in this opinion, the Fourth Amendment warrant requirement demands a showing of probable cause reasonable to the purpose being pursued. Thus, identification of purpose is necessary to assess the reasonableness of the probable cause standards at issue. Where multiple purposes are significant to an investigation, however, the Fourth Amendment does not require the government to identify a primary purpose or limit its ability to secure a warrant to satisfaction of the standards for that purpose. Rather, the government may secure a warrant under the probable cause standards applicable to any purpose that it pursues in good faith. Thus, we identify no constitutional defects in FISA’s certification requirement of “a significant” rather than a primary “purpose ... to obtain foreign intelligence information.” 50 U.S.C. § 1804(a)(6)(B). c. The “Primary Purpose” Requirement’s Origins as a Limit on the Executive’s Claimed Inherent Authority to Conduct Warrantless Surveillance for Foreign Intelligence Information To explain the basis for our decision, we begin by noting that the “primary purpose” requirement urged by Abu-Jihaad was originally formulated to address a constitutional concern not present in this case: the scope of presidential authority to conduct warrantless foreign intelligence surveillance. In United States v. United States District Court (Keith), 407 U.S. 297, 92 S.Ct. 2125, 32 L.Ed.2d 752 (1972), the Supreme Court rejected a claim of inherent executive authority to conduct warrantless domestic security surveillance, while specifically not deciding the scope of executive authority to conduct surveillance “with respect to activities of foreign powers or their agents,” id. at 321-22, 92 S.Ct. 2125 (emphasis added). The Fourth Circuit addressed that question in United States v. Truong Dinh Hung, 629 F.2d 908 (4th Cir.1980), a case involving warrantless foreign intelligence surveillance conducted before enactment of FISA, and resolved it favorably to the executive: “the Executive Branch need not always obtain a warrant for foreign intelligence surveillance,” id. at 913. At the same time, however, the court ruled that the executive’s power to act without a warrant was cabined by the Article II authority over foreign affairs from which it derived. Thus, Truong held that warrantless foreign intelligence surveillance was constitutionally authorized only with respect to “a foreign power, its agent or collaborators” and when “conducted ‘primarily’ for foreign intelligence reasons.” Id. at 915. Some twenty-eight years later, however, the FISA Review Court declined to impose a comparable primary purpose requirement on the warrantless surveillance provisions of the PAA, applicable to foreign powers or agents of foreign powers reasonably believed to be located outside the United States. See In re FISA Section 105B Directives, 551 F.3d at 1010-12 (holding that “more appropriate consideration” is whether “programmatic purpose of the surveillances ... involves some legitimate objective beyond ordinary crime control”). We have no occasion here to consider these warrantless surveillance decisions. We note simply that there is an important distinction between warrantless surveillances premised exclusively on executive authority, and surveillances pursuant to warrants issued by courts in compliance with standards enacted by Congress. The former require identification of an exception to the Fourth Amendment’s warrant requirement. See United States v. Duggan, 743 F.2d at 72 (collecting cases recognizing such exception); see also In re FISA Section 105B Directives, 551 F.3d at 1011-12. By contrast, the latter implement that requirement. Whatever purpose limits might be placed on the president’s authority to conduct warrantless surveillance to ensure that the exception does not extend beyond the constitutional ground for its recognition, it does not follow that the Fourth Amendment demands the same limitation when, as under FISA, the powers of all three branches of government — in short, the whole of federal authority — are invoked in determining when warrants may reasonably be sought and issued for the purpose of obtaining foreign intelligence information. Cf. Youngstown Sheet & Tube Co. v. Sawyer, 343 U.S. 579, 635-37, 72 S.Ct. 863, 96 L.Ed. 1153 (1952) (Jackson, J., concurring). d. The Fourth Amendment’s Warrant Requirement Is Flexible. As this court has recognized, the Constitution’s warrant requirement is “flexible,” so that “different standards may be compatible with the Fourth Amendment in light of the different purposes and practical considerations” at issue. United States v. Duggan, 743 F.2d at 72. Thus, when a surveillance warrant is sought for the purpose of investigating “ordinary crime,” the Fourth Amendment requires a showing of probable cause to believe that the target of the warrant “is committing, has committed, or is about to commit a particular offense,” and that “particular communications concerning that offense will be obtained through” the surveillance. 18 U.S.C. § 2518(3)(a) — (b); see Dalia v. United States, 441 U.S. 238, 255, 99 S.Ct. 1682, 60 L.Ed.2d 177 (1979). But when the government pursues a different purpose, such as obtaining security intelligence, “[djifferent standards” of probable cause reasonable to that purpose may support issuance of a warrant. See Keith, 407 U.S. at 322-23, 92 S.Ct. 2125. The considerations that the Supreme Court identified in Keith as distinguishing domestic security surveillance from the surveillance of “ordinary crime” and, therefore, as supporting different warrant standards, pertain equally to foreign intelligence surveillance: The gathering of security intelligence is often long range and involves the interrelation of various sources and types of information. The exact targets of such surveillance may be more difficult to identify than in surveillance operations against many types of crime specified in Title III. Often, too, the emphasis of domestic intelligence gathering is on the prevention of unlawful activity or the enhancement of the Government’s preparedness for some possible future crisis or emergency. Thus, the focus of domestic surveillance may be less precise than that directed against more conventional types of crime. Id. at 322, 92 S.Ct. 2125. Also noteworthy is Keith’s recognition of Congress’s particular competence to weigh these considerations and to establish reasonable warrant requirements for security surveillance, as distinct from those already prescribed for specified crimes in Title III. See id. at 322-23, 92 S.Ct. 2125. The benchmark for judicial review of the constitutionality of warrant requirements established by Congress is reasonableness: “Different standards may be compatible with the Fourth Amendment if they are reasonable both in relation to the legitimate need of Government for intelligence information and the protected rights of our citizens.” Id. at 322-23, 92 S.Ct. 2125. Consistent with this pronouncement, the Court in Keith observed that Congress might well judge that the application and affidavit showing probable cause for security surveillance “need not follow the exact requirements of [18 U.S.C.] § 2518 but should allege other circumstances more appropriate to domestic security cases; that the request for prior court authorization could, in sensitive cases, be made to any member of a specially designated court ...; and that the time and reporting requirements need not be so strict as those in § 2518.” Id. at 323, 92 S.Ct. 2125. This discussion in Keith informed our decision in United States v. Duggan, 743 F.2d at 72-74, upholding the warrant standards established by Congress in FISA for court-ordered surveillance to obtain foreign intelligence information. The PATRIOT Act did not modify the standards FISA applies to warrant applications for the purpose of obtaining foreign intelligence. Rather, it modified the degree to which foreign intelligence gathering must be the purpose of the surveillance. Thus, we need not here reconsider Duggan’s holding as to the reasonableness of FISA’s warrant standards for the purpose of obtaining foreign intelligence information. We need consider only whether any constitutional concerns are raised by Congress’s decision to allow FISA warrant standards to apply upon the executive’s certification that a “significant” rather than a “primary” purpose of the surveillance is to obtain foreign intelligence information. e. A “Significant” Rather than “Primary” Purpose to Obtain Foreign Intelligence Information Does Not Render FISA’s Warrant Standards Unreasonable (1) Duggan Recognized “Primary” Purpose as a Matter of Statutory Construction not Constitutional Mandate In concluding that the “significant purpose” certification requirement does not raise constitutional concerns, we note that when, in Duggan, we construed FISA’s original reference to electronic surveillance for “the purpose” of obtaining foreign intelligence information,” as a “requirement that foreign intelligence information be the primary objective of [any court-ordered] surveillance,” id. at 77 (emphasis added), we were identifying Congress’s intent in enacting FISA, not a constitutional mandate, see generally W.R. Grace & Co-Conn. v. Zotos Int’l, Inc., 559 F.3d 85, 88 (2d Cir.2009) (recognizing obligation “to look to the plain language of the statute to effectuate the intent of Congress”). This is evident from the fact that we articulated this construction in the context of determining whether the surveillance at issue in Duggan was conducted in accordance with FISA’s terms, not in the context of our earlier, and separate, determination of FISA’s constitutionality. See United States v. Duggan, 743 F.2d at 71-74. In short, nothing in Duggan erected a constitutional bar to Congress reconsidering and reframing the purpose requirement of FISA as long as it maintained warrant standards that in their totality were “reasonable both in relation to the legitimate need of Government for intelligence information and the protected rights of our citizens.” Keith, 407 U.S. at 323, 92 S.Ct. 2125. (2) Considerations Prompting Congress’s Adoption of the “Significant” Purpose Amendment In considering Congress’s decision to allow FISA standards to be triggered by a showing of a “significant” rather than “primary” purpose of obtaining foreign intelligence information, we may properly consider the “practical considerations” informing that choice. See Keith, 407 U.S. at 322, 92 S.Ct. 2125 (observing that different standards may be compatible with the Fourth Amendment in light of the “different policy and practical considerations” at issue); see also United States v. Duggan, 743 F.2d at 72. The relevant background is discussed in detail in In re Sealed Case, 310 F.3d at 722-29. We summarize it here only as necessary to highlight two considerations that emerged from years of Justice Department experience trying to satisfy the “primary purpose” requirement and that informed Congress’s amendment of FISA’s purpose certification provision: (1) if intelligence and law enforcement officials coordinate efforts in pursuing national security inquiries, it can be difficult, if not impossible, to identify whether their “primary” purpose is to obtain foreign intelligence information or evidence of a crime; and (2) the segregation of intelligence and law enforcement officials to ensure the executive’s ability to certify a “primary” foreign-intelligence-gathering purpose can compromise national security. FISA’s original purpose certification requirement was not uniformly construed by the courts. Although we thought it clear that the statute’s original reference to “the purpose” to obtain foreign intelligence information referenced the primary purpose, United States v. Duggan, 743 F.2d at 77, the First Circuit construed the requirement in the negative, holding that “the investigation of criminal activity cannot be the primary purpose” of a surveillance order under FISA, United States v. Johnson, 952 F.2d at 572. Meanwhile, the Ninth Circuit hesitated to define FISA’s purpose requirement “to draw too fine a distinction between criminal and intelligence investigations,” noting that “ ‘[international terrorism,’ by definition, requires the investigation of activities that constitute crimes.” United States v. Sarkissian, 841 F.2d 959, 965 (9th Cir.1988). The FISA Review Court echoed this concern in In re Sealed Case, questioning the soundness of any purpose certification standard that assumed “that the government seeks foreign intelligence information (counterintelligenee) for its own sake — to expand its pool of knowledge.” 310 F.3d at 727. It concluded that “FISA as passed by Congress in 1978 clearly did not preclude or limit the government’s use or proposed use of foreign intelligence information, which included evidence of certain kinds of criminal activity, in a criminal prosecution.” Id. In United States v. Duggan, we had “emphasize[d]” this same point, even though we construed “the purpose” requirement of FISA to mean “primary purpose”: [Otherwise valid FISA surveillance is not tainted simply because the government can anticipate that the fruits of such surveillance may later be used, as allowed by § 1806(b), as evidence in a criminal trial. Congress recognized that in many cases the concerns of the government with respect to foreign intelligence will overlap those with respect to law enforcement. 743 F.2d at 78. We concluded that where information sought through FISA surveillance “involved international terrorism[,] ... the fact that domestic law enforcement concerns may also have been implicated did not eliminate the government’s ability to obtain a valid FISA order.” Id. In the years after our decision in Duggan, this important point became muddled, if not lost. In 1995, the Justice Department not only committed itself to satisfying the primary purpose test but, “[apparently to avoid running afoul” of that test, it adopted procedures limiting contacts between intelligence and law enforcement officials. See In re Sealed Case, 310 F.3d at 727-28 (noting that procedures “eventually came to be narrowly interpreted within the Department of Justice” so as to erect a “wall” to “prevent the FBI intelligence officials from communicating with the Criminal Division regarding ongoing [intelligence] investigations”); see also The Nat’l Comm’n on Terrorist Attacks Upon the U.S., The 9/11 Commission Report 78-80 (2004) (discussing constraints imposed by “primary purpose” requirement on sharing of intelligence information between prosecutors and intelligence agents). Moreover, as the FISA Court became aware of these Justice Department procedures for segregating intelligence and criminal investigative officials, it “adopted elements of them” into certain of its orders. In re Sealed Case, 310 F.3d at 728. The net result was to shift “the focus” of FISA surveillance applications from the “purpose of the surveillance” to “the nature of the underlying investigation.” Id. As the FISA Review Court observed, these practices imposed a cost on national security. See id. at 744 & n. 29 (citing congressional hearings indicating that practices implemented to segregate intelligence from law enforcement officials to avoid running afoul of primary purpose test “may well have contributed, whether correctly understood or not, to the FBI missing opportunities to anticipate the September 11, 2001 attacks”). In the aftermath of September 11, 2001, the executive asked Congress to substitute “a purpose” for “the purpose” requirement of FISA so as to allow it to dismantle the wall between intelligence and law enforcement personnel erected to ensure that the primary purpose of any FISA surveillance or search was to obtain foreign intelligence information and not evidence of crime. Id. at 732. Congress did not accept the executive’s proposed language, but it did agree that certification of a primary purpose to obtain foreign intelligence information should not be required to secure a FISA warrant. Although no committee reports accompanied the PATRIOT Act, Senator Feinstein, one of the act’s strong supporters, provided a cogent floor statement as to the reasons for recasting FISA’s purpose certification requirement: Under current law, authorities can proceed with surveillance under FISA only if the primary purpose of the investigation is to collect foreign intelligence. But in today’s world things are not so simple. In many cases, surveillance will have two key goals — the gathering of foreign intelligence, and the gathering of evidence for a criminal prosecution. Determining which purpose is the “primary” purpose of the investigation can be difficult, and will only become more so as we coordinate our intelligence and law enforcement efforts in the war against terror. Rather than forcing law enforcement to decide which purpose is primary — law enforcement or foreign intelligence gathering, this bill strikes a new balance. It will now require that a “significant” purpose of the investigation must be foreign intelligence gathering to proceed with surveillance under FISA. The effect of this provision will be to make it easier for law enforcement to obtain a FISA search or surveillance warrant for those cases where the subject of the surveillance is both a potential source of valuable intelligence and the potential target of a criminal investigation. Many of the individuals involved in supporting the September 11 attacks may well fall into both of these categories. 147 Cong. Rec. S10591 (Oct 11, 2001) (quoted in In re Sealed Case, 310 F.3d at 732-33). To address these practical considerations — i.e., the difficulty in identifying the primary purpose when surveillance is pursued jointly by intelligence and law enforcement officials, and the importance of such joint efforts to protect national security — Congress in the PATRIOT Act amended FISA to provide that, upon satisfaction of all other statutory requirements, FISA warrants could be issued on certification “that a significant purpose of the surveillance is to obtain foreign intelligence information.” See Pub.L. No. 107-56, § 218, 115 Stat. at 291 (codified as amended at 50 U.S.C. § 1804(a)(6)(B)). In a separate amendment, Congress expressly authorized federal officers conducting surveillance with the aim of obtaining foreign intelligence information to coordinate their activities with law enforcement officers. See id. § 504, 115 Stat. at 364 (codified as amended at 50 U.S.C. § 1806(k)(1)) (“Federal officers who conduct electronic surveillance to acquire foreign intelligence information under this title may consult with Federal law enforcement officers or law enforcement personnel of a State or political subdivision of a State ... to coordinate efforts to investigate or protect against [, inter alia, actual or potential attack by a foreign power or agent of a foreign power, sabotage, international terrorism, or other clandestine intelligence activities by a foreign power or agent of a foreign power].”). In so doing, Congress made clear that such coordination would preclude neither a finding that FISA’s “significant purpose” certification requirement was met, nor the entry of an order of approval under § 1805. See 50 U.S.C. § 1806(k)(2). (8) A “Significant Purpose” To Obtain Foreign Intelligence Information Is Sufficient to Support the Application of FISA’s Standards to Surveillance Applications Abu-Jihaad does not dispute the considerations prompting Congress’s adoption of the “significant purpose” amendment. Rather, he argues that if FISA’s probable cause standards are applied without a “primary” government purpose to obtain foreign intelligence information, the executive will be able to manipulate FISA to obtain surveillance warrants for criminal investigations without demonstrating the probable cause required by Title III for that purpose. Because we conclude that the required certification of “a significant purpose” to obtain foreign intelligence information adequately protects against this possibility, we reject Abu-Jihaad’s constitutional challenge to this language. As Congress and the courts have recognized, government investigations relating to national security frequently pursue more than one purpose. See United States v. Duggan, 743 F.2d at 78 (stating that, in enacting FISA, “Congress recognized that in many cases the concerns of the government with respect to foreign intelligence will overlap those with respect to law enforcement”); see also In re FISA Section 105B Directives, 551 F.3d at 1011 (“A surveillance with a foreign intelligence purpose often will have some ancillary criminal law purpose.”). Indeed, multiple purposes may be inevitable given FISA’s definition of “foreign intelligence information” and “agent of a foreign power” by reference to serious criminal conduct. See In re Sealed Case, 310 F.3d at 724 (observing that “foreign intelligence information” as defined in FISA “ ‘can include evidence of certain crimes relating to sabotage, international terrorism, or clandestine intelligence activities’ ” (quoting H.R.Rep. No. 95-1283, at 49 (1978)) (emphasis omitted)); see also 50 U.S.C. § 1801(b) (defining “agent of foreign power” by reference to involvement in, inter alia, clandestine intelligence gathering, sabotage, and international terrorism). In such circumstances, intelligence and law enforcement purposes “ ‘tend to merge,’ ” making it difficult to identify one as primary. See In re Sealed Case, 310 F.3d at 724-25 (quoting S.Rep. No. 95-701, at 10-11, 1978 U.S.C.C.A.N. 3904, 3911-12 (1978)). Indeed, as experience has taught, if the executive is required to certify that its “primary” purpose in conducting surveillance is to obtain foreign intelligence information, it may well have to exclude law enforcement officials from playing any part in the surveillance. Such a segregation of purposes makes no sense in terms of protecting national security. See id. at 727 (“[I]f one considers the actual ways in which the government would foil espionage or terrorism it becomes apparent that criminal prosecution analytically cannot be placed easily in a separate response category.”). More important for our purposes, it is not compelled by the Fourth Amendment. For Fourth Amendment purposes, the critical question is not whether the executive can certify that obtaining foreign intelligence information is its “primary” purpose, but whether it can certify that it is a bona fide purpose of the surveillance. Thus, where the executive in good faith pursues both intelligence and law enforcement purposes, it may apply for surveillance authority under either FISA or Title III, provided it satisfies the particular warrant standards of the statute invoked. A Fourth Amendment concern would arise only if the executive, without a bona fide purpose to obtain foreign intelligence information, tried to secure a warrant under the standards identified in FISA as reasonable for that purpose. We need not here decide at what point a purpose advanced by the executive might be so trivial as to preclude it from being pursued in good faith. Congress adequately safeguarded against that possibility in FISA by demanding certification of “a significant purpose” to obtain foreign intelligence information, rather than simply “a purpose” as originally requested by the executive. Moreover, the FISA Review Court, whose rulings bind the FISA Court in issuing surveillance warrants under the statute, has construed the significant purpose standard to require “that the government have a measurable foreign intelligence purpose, other than just criminal prosecution of even foreign intelligence crimes.” Id. at 735. Indeed, the FISA Review Court has ruled that the significant purpose requirement specifically “excludes from the purpose of gaining foreign intelligence information a sole objective of criminal prosecution,” even for foreign intelligence crimes. Id.; see also id. at 736 (rejecting government’s argument that “significant purpose” requirement allowed it to have primary objective of prosecuting foreign agent for non-foreign-intelligence crime, and noting that “the manifestation of such a purpose” would “disqualify an application”). The FISA Review Court has also plainly ruled that the government’s certified purpose in seeking a FISA warrant is subject to judicial review. See id. at 735-36 (recognizing FISA Court’s authority to seek more information pertaining to government’s purpose). While “a significant purpose standard” eliminates “any justification for the FISA Court to balance the relative weight the government places on criminal prosecution,” if the court determines that the government’s sole objective is “merely to gain evidence of past criminal conduct — even foreign intelligence crimes — to punish the agent rather than halt ongoing espionage or terrorist activity, the application should be denied.” Id. at 735. Thus, the FISA Review Court has ruled that to satisfy the significant purpose test, it must appear that “the government entertains a realistic option of dealing” with the target of the FISA surveillance “other than through criminal prosecution.” Id. We do not here decide which, if any, of these FISA Review Court conclusions are constitutionally compelled. We conclude simply that FISA’s “significant purpose” requirement, so construed, is sufficient to ensure that the executive may only use FISA to obtain a warrant when it is in good faith pursuing foreign intelligence gathering, the purpose for which that statute’s warrant standards apply. The fact that the government may also be pursuing other purposes, including gathering evidence for criminal prosecution, compels no different conclusion. Accordingly, we reject Abu-Jihaad’s argument that FISA is unconstitutional because it does not require certification of a primary purpose to obtain foreign intelligence information. Rather, we hold that certification of a significant purpose to obtain foreign intelligence information, together with satisfaction of all other FISA requirements, is reasonable and, therefore, sufficient to support the issuance of a warrant under the Fourth Amendment. 2. FISA Was Lawfully Applied to This Case Abu-Jihaad submits that, even if FISA is not unconstitutional on its face, his conviction must be vacated because the statute’s conditions were not satisfied in securing some of the evidence supporting his conviction. Specifically, Abu-Jihaad contends that the government’s application for a surveillance order (a) failed to satisfy the “significant purpose” requirement of 50 U.S.C. § 1804(a)(6)(B); (b) failed to demonstrate probable cause to believe that he was an agent of a foreign power or that his telephones were being used or about to be used by a foreign power or agent of such a power, see id. § 1804(a)(3)(A)-(B); (c) included “clearly erroneous” § 1804(a)(6) certifications; and (d) was based on false statements, requiring a hearing under Franks v. Delaware, 438 U.S. 154, 98 S.Ct. 2674, 57 L.Ed.2d 667 (1978). Moreover, he faults the district court for deciding these questions against him without affording him access to the FISA warrant application papers and an adversarial hearing. a. The District Court Properly Denied Disclosure and a Hearing In FISA, Congress expressly provided that where, as here, the Attorney General certifies that “disclosure [of FISA materials] or an adversary hearing would harm the national security of the United States,” a district court must “review in camera and ex parte the application, order, and such other materials relating to the surveillance as may be necessary to determine whether the surveillance of the aggrieved person was lawfully authorized and conducted.” 50 U.S.C. § 1806(f). While the district court retains authority to order disclosure of FISA materials “under appropriate security procedures and protective orders,” it may do so “only where such disclosure is necessary to make an accurate determination of the legality of the surveillance.” Id. Where the court “determines that the surveillance was lawfully authorized and conducted, it shall deny the motion of the aggrieved person except to the extent that due process requires discovery or disclosure.” Id. § 1806(g). Mindful of these provisions, we have concluded that disclosure of FISA materials “is the exception and ex parte, in camera determination is the rule.” United States v. Stewart, 590 F.3d at 129 (internal quotation marks and brackets omitted). Here the district court found that “review of the FISA materials in this case [was] relatively straightforward and not complex.” United States v. Abu-Jihaad, 531 F.Supp.2d 299, 310 (D.Conn.2008). Further, while keeping “the requirements of the Constitution, the statute, and Duggan fixed firmly in mind[,]” the district court determined that disclosure and an adversary hearing were unnecessary because its in camera, ex parte review permitted it to assess the legality of the challenged surveillance and the requirements of due process did not counsel otherwise. Id. at 311 & n. 11. Upon our own review of the materials supporting the challenged FISA orders, we reach the same conclusions. Accordingly, we identify no denial of due process in the district court’s decision not to order disclosure of FISA materials to the defendant, or to conduct a preliminary hearing to rule on Abu-Jihaad’s challenge to FISA’s implementation in this case. b. The Government Satisfied FISA’s Warrant Requirements, and There is No Basis in the Record for a Franks Hearing In considering Abu-Jihaad’s claims that the government failed to satisfy the significant purpose, probable cause, and certification requirements of FISA, and proffered false information warranting a Franks hearing, we have conducted a careful in camera review of the challenged FISA orders, the government’s applications for those orders, and the classified materials submitted in support of those applications. We have similarly reviewed the government’s classified Memorandum in Opposition to the Defendant’s Motion for Suppression of FISA Evidence and Motion for Disclosure of FISA Applications, Orders and Related Materials and an Adversary Hearing; the classified declaration of Joseph Billy, Jr., Assistant Director of the Counterterrorism Division of the FBI; and the FBI’s classified declaration regardi