Largest intelligence agency

The National Security Agency (NSA) is the largest ­and most secretive institution of its kind. Often known as the 'No Such Agency', its mission is to gather information on the internatinal economic, diplomatic and military situation. Although accurate figures are impossible to confirm, it is understood that approximately 38,000 people work at the headquarters in Fort Meade, Washington, USA, with an annual budget exceeding $40 billion (then £23 billion). According to author James Bamford (USA), who has studied the NSA for years, each one of their dozen largest listening posts around the world picks up more than two million communications an hour including mobile phones, diplomatic traffic, emails and faxes. That works out at 500 million hours of data every day.