World of Warcraft screenshot than meets the eye. Our sister site WoW Insider is reporting that players have discovered hidden watermarks in every in-game screenshot that contains several pieces of information.
The watermark is made up of several strips of custom bar codes, which can be decoded to reveal information from the game. While the revealed information isn't extremely personal, it does contain the server IP, player account numbers, and a time stamp. The account number is publically accessable through Blizzard's Armory site and cannot be used to hack accounts.
WoW Insider says that this information is most likely used by Blizzard to take down private servers, rogue employees, and cheaters.