Messages of hate, tools for murder, and child pornography are the downside to having a free society. What's good is that we can stamp out child abuse and murder in ways other than censoring the Internet. (After all, murder and child abuse happened long before the Internet or computers were invented. We dealt with it then, we can deal with it now.)
When giving someone a freedom, you have to balance the good that freedom can do versus the bad the freedom can cause. The freedom of speech is important because the benefits outweigh the risk. Being able to freely discuss election results is more good than someone selling murder-for-hire is bad, because the functioning of society as a whole is more important than one person's right to not be murdered. (Imagine if the Internet were censored. Would we have heard about Diebold's faulty election machines? Would we have had a recount in Florida? Probably not: nobody would have been able to talk about it for fear of losing their domain name or Internet access.)
Censorship is the opposite of a freedom, but the same rules apply: will the "bad" that censorship prevents be worth the "good" that is suppresses? It's not going too well for China, so I'm not sure why we think it would be good in the US.
When giving someone a freedom, you have to balance the good that freedom can do versus the bad the freedom can cause. The freedom of speech is important because the benefits outweigh the risk. Being able to freely discuss election results is more good than someone selling murder-for-hire is bad, because the functioning of society as a whole is more important than one person's right to not be murdered. (Imagine if the Internet were censored. Would we have heard about Diebold's faulty election machines? Would we have had a recount in Florida? Probably not: nobody would have been able to talk about it for fear of losing their domain name or Internet access.)
Censorship is the opposite of a freedom, but the same rules apply: will the "bad" that censorship prevents be worth the "good" that is suppresses? It's not going too well for China, so I'm not sure why we think it would be good in the US.