Moderator removed all his posts & threads and from many other users

[kh99]

That would be a good start. I think the thread table contains information about the first and last posts, so any posts that end up being the first or last post probably needs special attention. If there are any attachments they'd need to be handled as well, if you care about those. There maybe be other things as well - hopefully someone else will know more.

A couple years ago we had a moderator remove a bunch of threads and I restored them from a backup by writing a script, but that's a bit different than restoring posts to existing threads.