I'm going to make this simple and clear:
WE DON'T WANT TO BATTLE HACKERS AND WE DO NOT WANT TO FACE HACKED POKEMON. If you use hacks, you can either stop and become a legitimate trainer or leave. We don't want you here. It's that simple.
Oh, and don't give me the junk about "because other people hack". If other people jump off a cliff, you'll do that too? And also don't give me the junk about "I got it from a trade, so I didn't hack." Well, you made the decision to use it, not those who traded to you. Plus, does it matter if someone else shot your aunt or you shot your aunt? If she's dead, then she's dead. This is the same thing.
Nonetheless, if you hack, then we will ban you. Simple as that.