It doesn't matter whether the name is hidden or not. This is very likely exactly the same person who threatened to reveal information about his daughter before. You yourself DQ cautioned that person not to go there. I think we all know exactly who it is.
I can resepect that you have a line you are not willing to cross, but the people who have really fired Charlie up are people exactly like this who keep coming at him and lurk under different usernames leaving him ever-cautious about who he lets into his forum. This just serves as a prime example as to how this type of behavior is helping to aggravate and promote Charlie's elevated response to things.