Certainly. But what if the forum is a private one (meaning that there is no coercion)? You join voluntarily, and in joining agree that the purpose of that association is so-and-so.
In that case, it is not censorship to yank comments and boot people. And, though unsound ideas are easily rebutted, it may not be the original purpose of that forum to rebut the particular unsound ideas spread by your particular visitors. Just because you can rebut them doesn't mean you should spend your time doing it.
The forum may be political in its purpose, but if it is private, it is apolitical in structure, and therefore libertarian principles would allow as much control over speech as the owners deem appropriate to attain the purpose.
So perhaps you actually ceded the agenda of your forum to others, in a misapplication of libertarian political principles of free speech to a private, purpose-driven discussion.
I wasn't criticizng FR, so much as explaining LF.
But if I did have a criticism to level at FR, it would be along the same lines. FR's stated purpose is to advance conservative ideas, and return the government to it's constitutional cage.
That used to be the prime force at FR. But in the last year or two, it seems to be moving more and more toward a GOP cheerleading site. And if that were owing to a simple shift in the balance of posters, that'd be one thing. But it isn't. It has much to do with a shift in the character of moderation and control. Dissent (even dissent in affirmation of conservative and constitutional ideals) is becoming increasingly untolerated. And suppression of those ideas, is met with cheers and hallelujia's from those who were prefer control rather than discussion.
Certainly this is Jim's site, and he's free to do with it as he pleases. And if he and his staff of moderators don't want to spend time rebutting statements which dare to affirm conservative and constitutional principles, even if it means they happen to be challenging the GOP staus-quo... then that's his choice.
But I think it's exacting a price on a once great beacon of freedom.
Will FR continue to have good numbers of devoted participants? Sure it will. Will it stand for ideas rather than men? That remains to be seen.