In the US they have (recently unsuccessfully, thank god) gone after people who did not upload but merely "made available" for upload. The idea being that even if you
didn't upload, but there was the possibility that you could have, they still will come after you.
How can this work in the context of bittorrent? Well, imagine an unpopular file with say 5 seeders, all with 100% of the file, and no leachers. You fire up the torrent, download the file from 5 different people, "seed" for a few minutes with no takers because you were off making dinner, then return to your computer and close your torrent client. You have just "made available" for 5 minutes, even though you never distributed anything.
Yeah, this crap has been thrown out recently, but that won't stop them from sending you "pre-litigation letters" demanding money, or from even hauling you off to court and forcing you to defend yourself.