Edit: obligatory explanation (thanks mods for squaring me away)…
What you see via the UI isn’t “all that exists”. Unlike Reddit, where everything is a black box, there are a lot more eyeballs who can see “under the hood”. Any instance admin, proper or rogue, gets a ton of information that users won’t normally see. The attached example demonstrates that while users will only see upvote/downvote tallies, admins can see who actually performed those actions.
Edit: To clarify, not just YOUR instance admin gets this info. This is ANY instance admin across the Fediverse.
Deleted items just get marked as ‘removed’, the content remains in the database. I can see the comment you deleted on https://lemmy.world/post/955546.
Overwrites appear to replace the original content. I can see when you edited this comment but can’t see what the edit was.
What happens if someone posts something illegal? Does the instance owner have to know enough SQL to remove the row and the image connected to it or is there a friendly way to do it in an admin interface?