From the AP article: Government guards papers from public eye

More than 1 million pages of historical government documents -- a stack taller than the U.S. Capitol -- have been removed from public view since the September 2001 terror attacks, according to records obtained by The Associated Press. Some of the papers are more than a century old. In some cases, entire file boxes were removed without significant review because the government's central record-keeping agency, the National Archives and Records Administration, did not have time for a more thorough audit. "We just felt we couldn't take the time and didn't always have the expertise," said Steve Tilley, who oversaw the program. Archives officials are still screening records, but the number of files pulled recently has declined dramatically, he said.