From today’s press release issued by National Security Archive: Proposed FOIA Exemption Would Provide National Security Agency (NSA) With Virtually Unchecked Power to Keep Records Secret. This release includes links to significant documents on related FOIA exemptions for intelligence agencies, prepared by the National Security Archive (such as this Side By Side Comparison of Statutory FOIA Exemptions for Operational Files from the CIA, NIMA, NRO and NAS), and the Federation of American Scientists’ Section-by-Section Analysis of FOIA exemption for the National Security Agency’s operational files.
See also this website for links to U.S. Intelligence and Security Agencies.