As I noted within my post #9955859@lemm.ee (alternate link), I found that thumbnail generation in Element is an enourmous privacy, and security vulnerability. Thumbnails are generated server-side, regardless of E2EE settings. What this means is that the URLs that one sends would be leaked out of your encrypted chats to the server.
OP can edit comment, sign with a different key and claim his comment was edited by the admins.
So we can’t know who really edited the comment unless in the default boring situation: it was OP and he signed it with the correct key which is the same as him just telling “yeah, it was me” or not saying anything at all since it’s the default.
Dang, that is a scenario that I hadn’t considered. I’m not sure that there’s anything that can be done about it.
Why not just host your own lemmy instance on a cheap vps and be satisfied you’re the only admin heh