@51, problem is that its impossible to prove that someone did delete a post to begin with. Or a topic. Nothing is saved when you delete a post or topic, and the internet archive doesn't take frequent enough snapshots of the website, for that to be viable. At most you can get a good circumstantial case against someone, but you can't prove it with evidence. You might raise the possibility of someone posting something about a post getting deleted, but an easy breaker of that argument is that I can definitely see some people claiming that someone deleted a post when they actually didn't. There's no way to prove it either way, which is the huge problem.

the difference between deleting your posts and deleting the thread is that only one of these deletes content by other users.  Delete posts, and everyone can still see the holes in the conversation.  But also, why is everyone so okay with posting on a thread, then having the OP delete the thread and take out the post you spent time writing?  Hope you didn't spend a long time on that post...

@55, most likely. This software has a very limited form of access control -- either everyone gets something or they don't. But there isn't much we could do about it.