Smurfing = Cheating

I'm sitting in mid diamond and I've come across so many smurfs who just ruin games, like not just a "hey I'm playing with my friends and I don't want to queue for an hour". These guys come into games, put up a 40-3 kd with a mercy pocket (of course) and then talk like they don't have the most fragile ego ever. Is Blizzard ever going to do anything about smurfs or are they just going to let them roam around and ruin our games?