Use the private messaging feature for private discussions, not the main board.
Try not to dwell on repeat trolls, it's really not a worthy discussion at all. When he does his thing he's dealt with. Feel free to send a PM to mods or report posts if you feel he's here unbeknownst to anyone, however we've caught him before he's even made one post every time so far, just waiting for him to basically post something for confirmation. Problem's taken care of though every time so he's hardly worth a topic guys, I wouldn't worry about it at all.