According to article by the Associated Press, the Central Intelligence Agency (CIA) goes through 5 million tweets a day.
At the agency's Open Source Center, a team known affectionately as the "vengeful librarians" also pores over Facebook, 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.
Reportedly, these "snapshots of opinion" are then compiled into a daily intelligence report for President Obama.