From PCMAG.com:
Before you tweet an inside joke about a terrorist movie like "United 93" or "Munich," you should know—the CIA might start following you.
CIA employees known as "vengeful librarians" monitor Facebook and Twitter feeds, TV news channels and radio stations, Internet forums and chat rooms, and pretty much any form of media that's open to the public, according to the Associated Press, which received an exclusive tour of the nondescript brick building in Virginia where all this takes place.