An explosive investigative series published in the Washington Post today begins, "The top-secret world the government created in response to the terrorist attacks of Sept. 11, 2001, has become so large, so unwieldy and so secretive that no one knows how much money it costs, how many people it employs, how many programs exist within it or exactly how many agencies do the same work." Among the findings: An estimated 854,000 people hold top-secret security clearances. More than 1,200 government organizations and nearly 2,000 private companies work on programs related to counterterrorism, homeland security and intelligence in 10,000 locations. We speak with Bill Arkin, the Washington Post reporter who wrote the piece with Dana Priest.

A hidden world, growing beyond control