You can’t delete a mail you sent me, nor put your hand written letter to me in the bin. I can keep both and I can keep your name and addresses in my little black book. So there isn’t even that level of privacy in the real old fashioned communication.

And communication over the Internet was always the subject of storage. Your mail may be on the backup tape of a mail server. Your usenet posting is on archive.

So the assumption that the fediverse can forget….