I don't think you will get ban as long as you are clean, but I'm sure they will check you every time somebody reports you of cheating. You'll know it if somebody reports you and you're clean, you'll get banhammer when you first open multiplayer and you'll get the message. You're a nice guy...etc etc. :)
Keep playing but don't cheat.
I also get those warning almost every week them banhammer and I'm a nice guy. :)