Players using cracked version of the game

Just noticed a guy today that could shoot me thru a tank when he was in a tank gunner seat, i jumped out on the other side of my team mates tank, i were not visible and i got killed by the enemy tank gunner, wich was a player named <edited name> as i searched for him to report possible cheat, i noticed he was not in the database.. I have heard about cracked copies of the game but did never think they would actually be able to play on the normal servers.

Anyways if he uses a cracked version, this is a serious problem!