National Security Letters (NSLs) are roughly comparable to administrative subpoenas. Various intelligence agencies use them to demand certain customer information from communications providers, financial institutions, and consumer credit reporting agencies under the Right to Financial Privacy Act, the Fair Credit Reporting Act, the National Security Act, and the Electronic Communications Privacy Act.

Five federal statutes authorize intelligence officials to request certain business record information in connection with national security investigations. The authority to issue these national security letters (NSLs) is comparable to the authority to issue administrative subpoenas. The USA PATRIOT Act expanded the authority under four of the NSL statutes and created the fifth. Thereafter, the authority has been reported to have been widely used. Prospects of its continued use dimmed, however, after two lower federal courts held that the lack of judicial review and the absolute confidentiality...