You mean someone was banned for being in a hacked game? I've been in games where you don't run out of ammo, get a crazy amount of points, but haven't been banned. But, when the game was over, I didn't get the points shown, so maybe that is the difference.

It's odd that they will ban someone for that, but not do anything about the cheats and hacks. Of course there is the possibility that he was cheating and got caught, but hey, what's 1 out of 1000's.

You do not get banned for getting into a hacked lobby and it adjusts your stats, you can get banned by IW from joining any of MW3 games if you are cheating (aimbot, wallhack etc.) and someone has sent a video to bancandy anti cheat team and they will punish the person.

If you get a "bans on record" tag on your steam profile this is to do solely with VAC (VALVE STEAM) the ban is due to the person using a cheat of some sort, heacking his stats, unlocking all perks, weapons, etc. or using a wallhack and/or aimbot, or the esp VAC disabler hack.

VAC bans are permanant and will never be lifted. He cheated plain and simple.