You don't have an identity on a torrent unless you join a server.
Similarly, you need to join a Lemmy server to have an identity there, or anywhere on Lemmy. Unlike private torrent trackers, you only need 1 Lemmy identity, and you can subscribe to other servers' communities from your original server.
Trackerless torrents are very old now, they use the DHT network to find peers. I believe it needs to be seeded when you first start a newly installed client, but that's completely transparent to the user.
