[yayr]

scheme 1: agents for copyright holders continuously scan for IP addresses who host copyrighted content and start legal actions.

scheme 2: criminal groups infect copyrighted content with malware to exploit downloaders of such content.

[harkinian]

Neither of those are against the bittorrent protocol itself. Lots of software like Ubuntu is legally available on bittorrent, and I've never seen anything done to restrict that.