[__MatrixMan__]

In principle, pretty much any crime you can commit over tor, you can also commit over BitTorrent. For instance, you could advertise your assassination services by writing up a document, making a torrent of it, and then distribute the magnet link for that torrent on floppy diskettes... or whatever.

In practice, though, TOR is more convenient for such things because a resource's name (the onion address) doesn't change when the content does. This difference makes it rather unlikely that you're going to find the lets-make-an-illegal-deal crowd gathering around BitTorrent.

But legally, and from the ISP's perspective, seeding a torrent with incriminating content is no different than running a TOR exit node that happens to be trafficking that content--it's just that since they attract different crowds, one is more likely to attract the wrong kind of attention than the other.

Also, you get to choose what you seed on BitTorrent, but when you run an exit node, you don't. So you're unlikely to even know what kind of incriminating content is going through your internet connection.