A national security letter (NSL) is an administrative subpoena issued by the United States federal government to gather information for national security purposes. NSLs do not require prior approval from a judge. The Stored Communications Act, Fair Credit Reporting Act, and Right to Financial Privacy Act authorize the United States federal government to seek such information that is "relevant" to authorized national security investigations. By law, NSLs can request only non-content information, for example, transactional records and phone numbers dialed, but never the content of telephone calls or e-mails.