People are acting like this is surprising news. I guess people don't actually understand how BitTorrent works, which is troubling. When you connect to a peer on

People are acting like this is surprising news. I guess people don't actually understand how BitTorrent works, which is troubling. When you connect to a peer on BT, you have to be told its IP address (or that of a proxy, and most users obviously aren't using them) in order to connect to it. You can easily then run a reverse IP lookup on that address and usually find out the ISP. Matching that to the initial seeder should be pretty trivial so long as you get to the torrent quickly enough after it was first seeded so you can see who the only person with 100% is. Even if you can't get to it before there are a handful of seeders, you should be able to narrow it down by looking for the common IP among several torrents.