The Telegraph 
Friday, November 4, 2011
In an anonymous industrial park in Virginia, in an unassuming brick building, the CIA is following Twitter and Facebook in an effort to stay ahead of America’s enemies.
At the agency’s Open Source Centre, a team known affectionately as the “vengeful librarians” also pores over newspapers, TV news channels, local radio stations, Internet chat rooms – anything overseas that anyone can access and contribute to openly.
From Arabic to Mandarin Chinese, from an angry tweet to a thoughtful blog, the analysts gather the information, often in native tongue.
They cross-reference it with the local newspaper or a clandestinely intercepted phone conversation. From there, they build a picture sought by the highest levels at the White House, giving a real-time peek, for example, at the mood of a region after the Navy SEAL raid that killed Osama bin Laden or perhaps a prediction of which Mideast nation seems ripe for revolt.
Full story here.