CRS – Overview of Constitutional Challenges  to NSA Collection Activities and Recent Developments. Edward C. Liu , Legislative Attorney; Andrew Nolan, Legislative Attorney; Richard M. Thompson II; Legislative Attorney, April 1, 2014

“Beginning in the summer of 2013, media reports of foreign intelligence activities conducted by the National Security Agency (NSA) have been published and are apparently based on unauthorized disclosures of classified information by Edward Snowden, a former NSA contractor. The reports have focused on two main NSA collection activities conducted under the  auspices of the Foreign Intelligence Surveillance Act (FISA) of 1978. The first is the bulk  collection of telephony metadata for domestic and international telephone calls. The second  involves the interception of Internet-based communications and is targeted at foreigners who are not within the United States, but may also inadvertently acquire the communications of U.S. persons. As the public’s awareness of these programs has grown, Members of Congress and the public have increasingly voiced concerns about the constitutionality of these programs. This report provides a description of these two programs and the various constitutional challenges that have  arisen in judicial forums with respect to each. Although a brief overview of the constitutional  arguments and issues raised in the assorted cases is included, a detailed analysis or evaluation of those arguments is beyond the scope of this report.”