Does anyone realize the amount of resources it would take for every single game save data file to be examined to determine who hacked and who didn't? You purchased the product and chose to alter your very own data. This, by no means, directly affects other player's in game experience. My guess would be that, simply, you won't be able to use the hack anymore and thats it. BTW, IW can't ban you from PSN, only Sony can. During this console war, do you really think Sony wants to turn away a customer because you changed your MW2 emblem? They will do enough in order to ensure their prodcut still sells and continues to make money. Remember, this is a business and IW wants to make money now and in the future.
Common sense.