LOL, World of Warcraft players use virtual snowballs to deal with Gold Farmers:

World of Warcraft players have discovered a more direct and more satisfying way of dealing with „gold farmers“. The farmers make real money by exchanging dollars for virtual gold. Regular players are often annoyed when these farmers send multiple messages over the citywide chat in the major towns of Ironforge and Ogrimmar. WoW administrators have rarely stepped in to stop message spamming, but players on the Medivh server have found that a well thrown virtual snowball gets the point across much more effectively…. We witnessed one gold farmer get pelted with dozens of snowballs after she sent several „Want to Sell“ messages over Ironforge’s city chat. Over several minutes, the farmer was bombarded with more than a hundred snowballs and fled out of the city. Eventually, the spamming stopped.