I think we've seen in other topics there is definitely at least one hacker involved in this whole situation. Someone broke into Cheryl's computer, another was in Joyce's... It's completely possible that is him/her, and if it's not, they may know the person. So there actually is the chance they have access to the IP adresses of anonymous posters.
And don't say, "Post your name, anon," when you're anon and not posting yours. Hypocrite.