FrozenBBS

http://w11.zetaboards.com/frozenbbs/
No restrictions of using anonymizing networks/proxies
No Captcha. Accounts(optional) however must be approved by Admin.
Guest and Account based posting on all forums
Separate forums for various topics and interests, you can request new subforums.
Strict moderation. No shitposting will be tolerated.

Oh now you're moving them into super-specialized sub-sub-sub-forums. Good move, you're good at this.

>>15
On frozenbbs you don't post threads, you post boards.
That way threads are never off topic.