ToyKeeper and other wrote in with this: "The Register published a detailed analysis of BitTorrent traffic and user habits today, focusing on four aspects: availability, integrity, download speeds, and ability to withstand flash crowds. BitTorrent carries 53% of all P2P traffic (or ~35% of all 'net traffic), and this paper helps explain why. Also included are data about torrent lifetime, network poisoning, response during downtime or attacks, and lots of pretty charts. A few performance problems are revealed, which will hopefully be addressed in future p2p systems." The original paper (pdf) is available.