The National Security Agency is a U.S. intelligence agency responsible for global monitoring, collection, decoding, translation and analysis of information and data for foreign intelligence and counterintelligence purposes - a discipline known as Signals intelligence. NSA is also charged with protection of U.S. government communications and information systems against penetration and network warfare. The agency is authorized to accomplish its mission through clandestine means, among which are bugging electronic systems and allegedly engaging in sabotage through subversive software. Originating as a unit to decipher coded communications in World War II, it was officially formed as the NSA by Harry S. Truman in 1952. Since then, it has become one of the largest of U.S. intelligence organizations in terms of personnel and budget, operating as part of the Department of Defense and simultaneously reporting to the Director of National Intelligence.