There are many things a person can do that are immoral that are not necessarily against the law. The law is not the same as morality.
GetMagnaCarter explained it best.
It's not censorship. The law doesn't force every business to publish anything that customers want them to. Censorship is when the government or equal authority uses force or the threat of force to force you to not publish something. GameFAQs is a business that publishes people's messages (along with guides, cheats, etc). It is not censorship for them to decide not to publish something. It is also not immoral because businesses that publish things are not morally compelled to publish everything put before them.
I don't think I can make it any clearer.
Censorship is not a term that is limited to government quelling of speech, you're confusing it with freedom of speech. For example, Muhammad was censored on South Park.