If all the Americans cleared to access classified information lived in the same US city, it would be second only to New York City in population, USA Today finds in the wake of the NSA's leaked surveillance program. More than 4.9 million people have some kind of government security clearance, with 1.4 million of those able to access information classed as "top secret," according to the Office of the Director of National Intelligence.
Not all of those able to access state secrets are government employees, with close to a million security clearances held by contractors. Clearances, which require longer and more expensive investigations the higher up the ladder you go, tend to involve checks on basic information and interviews with associates, though a Government Accountability Office report last year slammed intelligence officials for failing to bring in standard policies for government agencies to "determine eligibility for access to classified information." (Read more security clearance stories.)