http://projects.washingtonpost.com/top-secret-america/ http://projects.washingtonpost.com/top-secret-america/ Millions is probably overstating it though. FTA:

http://projects.washingtonpost.com/top-secret-america/ http://projects.washingtonpost.com/top-secret-america/ Millions is probably overstating it though. FTA: "An estimated 854,000 people, nearly 1.5 times as many people as live in Washington, D.C., hold top-secret security clearances." Which might place a rough estimate of tens to hundreds of thousands (depending on how many would be in the Military, work directly for the Govt, or work on other programmes)