Going completely by common sense, I conclude that censorship is good and necessary for the common good.
First, read this short post:
http://www.cathinfo.com/catholic.php/Stating-the-obvious-Websites-are-convincingI establish that any website run by a person of average intelligence or better is going to sound convincing, when taken in isolation.
If I had more time, I'd demonstrate. Have you ever read two opposing websites and found it hard to pick who sounds the most convincing? If so, you know what I'm talking about.
So if error can be so DAMN convincing (pardon the pun), it follows that it shouldn't be given the light of day.
It's not as though people will naturally gravitate towards the truth. No, the wounds of Original Sin involve a dulling of the intellect so we can get things wrong now.
That's why we shouldn't "expose children to everything, and trust that they'll choose the good and the true" because there's no guarantee.
If anything, they'll be MORE LIKELY to choose error, since it caters to fallen human nature!So it would be a mistake, under the guise of fairness, to give "equal play" to those in error as well as those possessing the truth.
The only exception to this (which isn't an exception, really!) would be cases that are in dispute -- where the truth is not known with SCIENTIFIC certainty. Moral certainty is sufficient for making a moral choice. But I don't believe that being "morally certain" that someone is wrong is enough reason to ban/censor them.