“It IS possible to have files change from a host running a hacked lobby,” the poster writes “VAC is triggered because a users files were unwillingly overwritten or changed, and they get banned via no fault of their own. An intriguing theory offered by one poster suggests that it is old Quake 3 dedicated server code (being reused in Modern Warfare 2) that is to blame. This is a pretty no-nonsense system, but the recent recipients of Modern Warfare 2 bans have been protesting their innocence – in numbers which appear to suggest they have some justification.
VAC is an integrated component of Steam and, as the FAQ in Steam’s dedicated VAC forum states: “Your account got banned because VAC detected a cheat being used with your account. Doubts are being raised over the infallibility of Valve’s Anti-Cheat system (VAC,) after an unknown number of Modern Warfare 2 players were banned over the last few days.
