A user who has deleted their LW account. It's actually pretty easy to find out who, but it seems kinda rude to say publicly since they presumably had a reason for the deletion. Someone who I bet is the same person has I-think-still-active accounts under the same or very similar names elsewhere on the internet.

If knowing that it's not hard to find out who wrote the post isn't enough to enable you to do it, PM me and I can tell you. This doesn't constitute an offer to tell anyone else; even this much seems a little rude to the original author.