It happened in the neighborhood of Calima, north of the city of Cali, Colombia. Two men arrived to an internet cafe, rented two computers, did their thing for a bit and, as they pretended to be paying, they took out guns and got all the money.
One of the two robbers forgot to log out of his Facebook account. Police used it to trace his home address.
Link (Google Translate) -via Gizmodo
Photo (unrelated) via Flickr user glenmcbethlaw