Steven Aftergood has a good post about the CIA Records Search Tool (CREST): CIA’s CREST Leaves Cavity in Public Domain, by Steven Aftergood, Secrecy News, April 6, 2009. Among other things he points to the new article in Mother Jones:

• Inside the CIA's (Sort of) Secret Document Stash. by Bruce Falconer. Mother Jones. 3 Apr 2009.

The article notes that the CIA monitors users of the FOIA documents:

Next to the computer terminals is a sign warning that "the CIA will gather and store information about your visit automatically" (a message driven home by two overhead video cameras encased in tinted glass) and that "unauthorized attempts to modify any information stored on this system, to defeat or circumvent security measures, or to utilize this system for other than its intended purposes are prohibited and may result in criminal prosecution."

See also: CIA Records Search Tool (CREST).