Cheating in school on tests, homework, etc: BADDD. I agree with Dogboy since cheating doesn't help you, it only hurts you. You are also dragging the other person(s) into your sorrow fest when you attempt to copy.
Now, most would think I'm against cheating in video games; however, I am not. If you happen to purchase a game and cheating device, then you could go all out on your hacking for all I care. You're in your own little world, so no one will be bothered if you get your million items or whatever. I'm against scamming, particularly with wifi, because then it is "dragging" in those whom do not wish to be ripped off or cheated from.
Cheating on people.. haha. Oh God, you are really screwing up with someone's feelings. That's very bad too. :<
Let's see.. You probably didn't intend this either, but another form of cheating is in sports. I wouldn't support that either for obvious reasons; it could change the outcome of huge events and such.