The National Security Agency was founded in World War I as a unit for deciphering coded communications. It was officially organized as the NSA in 1952 by President Harry S Truman. Since then the NSA has become one of the largest-funded intelligence organizations in the U.S. and operates under Department of Defense (DoD) jurisdiction, reporting directly to the Director of National Intelligence.

The NSA does not have the authority to conduct human-sourced intelligence gathering and espionage, as opposed to the other intelligence organizations in the U.S., the Defense Intelligence Agency (DIA) and the Central Intelligence Agency (CIA). Rather, the main mission of NSA is electronic and broadcast intelligence gathering, which is the collection of electronic intelligence in the form of data. They do this by monitoring the broadcast airwaves, especially the largest communication network in the world, the Internet.