AT&T Could Cut Off P2P Users
malign noted that AT&T has stated that using P2P on their 3G wireless network is grounds for disconnection. The lobbyist told congress "Use of a P2P file sharing application would constitute a material breach of contract for which the user's service could be terminated."
From World of Warcraft players.
At the next patch/update of the game, you'll receive a boatload of calls from angry customers.