Federated services have always had privacy issues but I expected Lemmy would have the fewest, but it’s visibly worse for privacy than even Reddit.
- Deleted comments remain on the server but hidden to non-admins, the username remains visible
- Deleted account usernames remain visible too
- Anything remains visible on federated servers!
- When you delete your account, media does not get deleted on any server
Blockchains have the property of being append-only, so a blockchain is precisely what makes it impossible to delete transactions. That being said, in a distributed system, once the message leaves trusted servers, it is obviously also impossible to delete it.