Valve "erroneously" banned 12,000 gamers for cheating playing Modern Warfare 2 on Steam. In an email today, Gabe Newell, President of Valve, apologised to the banned and confirmed that their accounts were restored. To make amends, the company has given all affected two free copies of Left 4 Dead 2, one to own and one to give to a fellow Steamer. Valve deploys an automated piece of software called Valve Anti-Cheating, or VAC, on Steam. Over the last two weeks It pushed out false positives on the 12,000 gamers, following a "combination of conditions occuring while Steam was updating the disk image of a game".
