"More than 267 million Facebook user phone numbers, names and user IDs were exposed in a database that anyone could access online, adding to a long list of privacy and security mishaps that continue to plague the world's largest social network.
Security researcher Bob Diachenko discovered the trove of Facebook user data on Dec. 14. The database, which has been pulled down, wasn't protected by a password or any other safeguard. Access to the database was removed, but by then the information had been out in the open for nearly two weeks. Someone had also made the data available for download on a hacker forum, according to Comparitech, a UK technology research firm that worked with Diachenko."