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."
That and the "unlimited service" means "we'll kick you off if you use over 5 gigs".
The World Wide Web is dying. Soon, we shall have only the Internet.
Quoted from AT&T Wireless's Service Agreement (emphasis mine). So yes, they can in fact charge you the fee if they are the ones canceling the contract.