In fact, it would be cool if there were a forum that was moderated based on those principles.
I.e. "ought" beliefs would be moderated against evil, such as Nazism, paedophilia, ethnic supremacy (but only on the moral level of "X 'superior' race is entitled to the land and resources of Y 'inferior' race", not on the factual level of "X race is on average better at Z skill than Y race"), promotion of other kinds of violence, totalitarian regimes, etc.
But "is" beliefs would be completely free, even when they seem (to minds who don't recognise the fact-value gap) to promote something evil.