The National Security Agency (NSA) is an intelligence agency of the United States Department of Defense, under the authority of the director of national intelligence (DNI). The NSA is responsible for global monitoring, collection, and processing of information and data for global intelligence and counterintelligence purposes, specializing in a discipline known as signals intelligence (SIGINT). The NSA is also tasked with the protection of U.S. communications networks and information systems. The NSA relies on a variety of measures to accomplish its mission, the majority of which are clandestine. The NSA has roughly 32,000 employees.
Originating as a unit to decipher coded communications in World War II, it was officially formed as the NSA by President Harry S. Truman in 1952. Between then and the end of the Cold War, it became the largest of the U.S. intelligence organizations in terms of personnel and budget. Still, information available as of 2013 indicates that the Central Intelligence Agency (CIA) pulled ahead in this regard, with a budget of $14.7 billion. The NSA currently conducts worldwide mass data collection and has been known to physically bug electronic systems as one method to this end. The NSA is also alleged to have been behind such attack software as Stuxnet, which severely damaged Iran's nuclear program. The NSA, alongside the CIA, maintains a physical presence in many countries across the globe; the CIA/NSA joint Special Collection Service (a highly classified intelligence team) inserts eavesdropping devices in high-value targets (such as presidential palaces or embassies). SCS collection tactics allegedly encompass "close surveillance, burglary, wiretapping, [and] breaking".
