6 FBI v. FAZAGA Opinion of the Court security interests of the United States.” App. 26, Decl. of Eric H. Holder ¶1. This claim applied to the following categories of information: information that could “confirm or deny whether a particular individual was or was not the subject of an FBI counterterrorism investigation,” information that could reveal the “initial reasons” for or the “status and results” of an “FBI counterterrorism investigation,” and information that could reveal the “sources and methods” used in such an investigation. Id., at 28, ¶4. An Assistant Director of the FBI filed a public declaration explaining why disclosure “reasonably could be expected to cause significant harm to national security,” id., at 60, Decl. of Mark F. Giuliano ¶32, along with a more detailed classified declaration. After reviewing both “the public and classified filings,” the District Court held that the state secrets privilege required dismissal of all respondents’ claims against the Government, except for the claim under FISA, 50 U. S. C. §1810, which it dismissed on sovereign-immunity grounds. 884 F. Supp. 2d 1022, 1049 (CD Cal. 2012); 885 F. Supp. 2d 978, 982–984 (CD Cal. 2012). The District Court concluded that litigation of the claims it dismissed “would require or unjustifiably risk disclosure of secret and classified information.” 884 F. Supp. 2d, at 1028–1029. The Ninth Circuit reversed in relevant part and held that “Congress intended FISA to displace the state secrets privilege and its dismissal remedy with respect to electronic surveillance.” 965 F. 3d 1015, 1052 (2020). That holding depended on two subsidiary conclusions. First, the Court of Appeals held that “§1806(f ) procedures are to be used when an aggrieved person affirmatively challenges, in any civil case, the legality of electronic surveillance or its use in litigation, whether the challenge is under FISA itself, the Constitution, or any other law.” Ibid. Second, the Court of Appeals held that, where §1806(f )’s procedures apply, it “speak[s] quite directly to the question otherwise answered