Smurfers...

Make Smurfing a reportable offense... it ruins the game for other people by placing people of infinitely higher skill against those of lower, and thus results in unfair, and boring games. It is unbelievably low for someone to do this, and then they act all high and mighty and when someone calls them out on it act as if they're the most toxic thing in the world despite them being a troll abusing the system...