Whilst I agree that the Tor network would be better off without Bittorrent traffic, it bothers me when I read things that say that Tor can't anonymise Bittorrent traffic.

https://trac.torproject.org/projects/tor/wiki/TheOnionRouter...

Using the TransparentProxy mode of Tor, forces all network traffic out through Tor, and blocks stuff which can't be, such as UDP. Do that on a machine which only has a LAN address so doesn't know it's Internet facing IP, and it's anonymous... It can't leak it's IP because it doesn't know it, and it can't connect to the Internet without going via Tor...