Washington Post today unveils the first installment of a a three-part multimedia report on Top Secret America, the results of a two-year investigation which includes an interactive map, database and video.

The lead story, A hidden world, growing beyond control by Dana Priest and William Arkin, 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.

These are some of the findings of a two-year investigation by The Washington Post that discovered what amounts to an alternative geography of the United States, a Top Secret America hidden from public view and lacking in thorough oversight. After nine years of unprecedented spending and growth, the result is that the system put in place to keep the United States safe is so massive that its effectiveness is impossible to determine.

Related: Internal Memo: Intelligence Community Frets About Washington Post Series. Marc Ambinder at the Atlantic:

Below, a memorandum sent two weeks ago by Art House, director of communications for the Office of the Director of National Intelligence, to public affairs officers in the intelligence community about the Washington Post's upcoming series on contractors. In the memo, House discloses that the series has been in the works for two years, includes an online database of contractors and their projects, and a television partnership with PBS's Frontline. House outlines what he thinks the story will conclude, and provides a guide of sorts for the intelligence community to prepare its response.

Is Wash Post harming intelligence work? at the Washington Times reproduces a "Notice to Industry Partners" sent by the Office of the Director of National Intelligence.