Or, move on and think, "It's just a game", neg rep them, and never have to play with them again.
I just never get the hard on people have for wanting to have modders raped and pillaged. Yea, it's against the "agreement" in the XBL contract, but, if you read that, so is swearing, so why not report everybody who swears? They're breaking the rules too.
It's simple, you join a game, realize people are modding/hacking, neg rep them, leave the game, and find another. Let all the modders/hackers play with each other.
There are more threads bitching about modders/hackers/glitchers than there really need to be.