The SCS is a U.S. black budget program that has been described as the United States' "Mission Impossible force", responsible for "close surveillance, burglary, wiretapping, breaking and entering". It is headquartered in Beltsville, Maryland, next door to the U.S. Department of State's Beltsville Communications Annex, and is jointly staffed by the Central Intelligence Agency (CIA) and National Security Agency (NSA). SCS operatives are based out of U.S. embassies and consulates overseas, and operatives often use Foreign Service or Diplomatic Telecommunications Service cover when deployed. Their mission is to intercept sensitive information on espionage, nuclear arms, terrorist networks, drug trafficking and other national-security-related issues.