Electronic surveillance and the National Security Agency

"Electronic Surveillance and the National Security Agency: From Shamrock to Snowden is a collection of leaked and declassified records documenting U.S. and allied electronic surveillance policies, relationships, and activities. It serves as an addition to several National Security Archive documents sets -- including those on U.S. Intelligence and the National Security Agency. The records provide information on the limitations imposed on electronic surveillance activities, organizations, legal authorities, collection activities, and liaison relationships."