An adult should be capable of consuming information from disparate sources, especially distasteful ones, and formulating logical arguments to deconstruct those positions. It takes some practice. That practice can't be done in an information vacuum. If there are deficiencies in the population's ability to perform the above, then we should be rectifying that through education (whereby I mean improving how people go about mentally solving problems), rather that scrubbing the world of "bad" data or opinions.
Entrusting institutions to ban media is essentially saying "These people know what's good for you, better than you do." and I absolutely abhor that sort of arrogant, misplaced, condescension. It often comes from people who are intelligent, but nowhere near as infallible as they think they are.