Yes, but presumably he's the head honcho of his own forum, is he not? In my books, that makes him a one-man band. A few acolytes doth not even a cult make.
He reminds me of that great film (name escapes me) starring Brian Dennehy (imho possibly the most underrated actor in the history of Hollywood) as the southern control-freak head of a violent family cult. It was a chilling character study of the inevitable consequences that follow when a socio/psychopath uses religion to enforce his reign of terror.
Our 'friend' is likely only one step removed from Dennehy's character. He should see the film, then report back here if he recognises himself at all in the character.