Make private forums because it's annoying when a troll makes fun of you
He means that it would be made so you could only access a private forum if you had a certain code or the person who made the forum gave you permission or something. (Mods would be allowed into all, of course.)
Honestly, other than his intro thread, every shitpost that Bingbing has made has gotten deleted either by me or someone else. Seems like the more practical thing to do is to ban Bingbing.
I'd say the only sane thing to do is give him his own private forum, where nobody else can post, and exclude him from the main ones.