A BitTorrent client uploads data to other peers who want the data blocks you have already downloaded (even while you're still in the process of downloading the

A BitTorrent client uploads data to other peers who want the data blocks you have already downloaded (even while you're still in the process of downloading the content, depending on the peers in the swarm around that time). I think it'd be difficult to argue technically that you were just downloading and not uploading when using BitTorrent. If you leave the torrent running after the download completes, you're seeding (uploading) to any other user's client that connects to yours and asks for blocks from your client.