Valve has made server-side fixes to stop people cheating when playing Left 4 Dead on Xbox 360.
"Valve has released a server-side fix to deny the recently reported cheats on all dedicated Left 4 Dead Xbox 360 servers," says a statement from the developer on Blue's News.
"The fix is designed to halt the cheating behaviour on the dedicated servers, which accounts for the majority of the co-op and Versus modes of play.
"A title update for those playing on user-hosted servers and/or via system link will be released in the coming days."
Cheating involved using a mod to unlock PC-style console commands, which grant control over nearly all of the content; spawning baddies and weapons, giving infinite health, making things disappear and turning characters into giants.
There's a video of the cheats in action on YouTube.