I play GTA IV on XBox Live and recently, and I have seen several people somehow using cheats in the game. Some cars are extremely fast, there's no way that it's possible in game (sometimes it's a bus and they wreck havoc on other players)
Sometimes they spawn new colourful helicopters, or become god so no matter how many bullets I put in their heads, from 2 inches away, they just stand there looking at me and then walk away.
At other times, they appear to be in a building (or, they ARE that building?) and I can never kill them, yet they can kill me.
How is it done? I have tried to search for this forever and cannot find one single clue to this. Also, how do I avoid getting into those kind of games?