In the first report of its kind, the Associated Press has learned that the Central Intelligence Agency is following tweets, up to 5 million a day.

An art student in Cairo paints the Facebook logo on a mural commemorating the revolution that overthrew Hosni Mubarak. (Manoocher Deghati/AP)

The agency's Open Source Center, as it is called, gathers information, often in a country’s native language, to get a picture of the mood of a region after a world event, or a prediction of what might come.

The center followed Chinese-language tweets to find out China wasn’t pleased with Osama bin Laden’s death, for example, and knew months before that an uprising in Egypt was coming, though they couldn’t predict when.

The center was set up in response to a recommendation by the 9/11 Commission; its focus was to be on counterterrorism and counterproliferation. But the AP reports that its several hundred analysts (the actual number is classified) have since begun to track a broad range of information, which goes into President Obama's daily intelligence briefing almost every day.

The center’s director, Doug Naquin, says the most successful analysts at the center have library science degrees (hence the ‘vengeful librarians”), speak multiple languages, and are like the computer hacker heroine of the crime novel “The Girl With the Dragon Tattoo,” because he or she “knows how to find stuff other people don't know exists.”