"just because BitTorrent is sometimes used for piracy."
Er no almost all of BitTorrent traffic is piracy some say upto 99.7% of it is.
http://arstechnica.com/tech-policy/2010/07/only-03-of-files-on-bit-torrent-confirmed-to-be-legal/
Contrary to geek fantasy the world and its dog isn't downloading linux distros via bittorrent on a daily basis, or massive games from the publishers. They are downloading films, music, and tv shows.