Yeah but from the point of view of the (unexpecting) uploader that doesn't change anything. If user A wasn't uploading, user B would still get the files from other peers on the torrent, doesn't change the fact A was sharing and actively uploading the file.

Not trying to throw a wrench in your game, but I think this is something you guys need to have a look into because you're turning unsuspecting users into uploaders of content they have no control over, without noticing it, when it has been proven to cause them legal harm.