It's now possible to use an encryption system called Protocol Encryption (PE) on BitTorrent P2P file-sharing traffic.
I confess to using BitTorrent to grab US TV programs before they're broadcast in the UK or, occasionally, when I've missed a program I really should have recorded on my Sky Plus box, but didn't.
Typical P2P file transfers on, for example, the new series of Lost, is around 20,000 bps on my 2 Mbps home Plus.net service. Using uTorrent, the P2P file transfer schlepped up to 1.5 Mbps.
Hmmm - I think Plus.net are really throttling my home broadband connection. Mind you, they're cheap...