I can't believe I'm writing this. I can't believe anyone has to write this. I am certain that writing this will not make me many friends here...
The First Amendment to the United States Constitution, proposed in 1789 and ratified in 1791, states, "Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances."
I mention this because of a thread I read this evening here on MMORPG.com. While somewhat amusing (I never knew it was possible to get so angry and full of rage over forum moderation!) and, frankly, somewhat astounding that the thread can actually still be read, the OP's forum handle and comically outraged choice of words clearly demonstrates why the moderation occurred in the first place. In the midst of a colorful rant, the OP tosses out a comment about freedom of speech.
I have seen this argument over and over, usually on gaming forums owned by private entities such as MMORPG.com, Sony Online Entertainment, Blizzard Entertainment, Cryptic, BioWare (and all of their respective parent companies), and other, more loosely moderated gaming forums. The problem with the "First Amendment/freedom of speech" argument is that many people tossing it around were not properly taught US History or Civics in school, because the argument does not apply in a forum situation.
Let's look at the First Amendment again:
"Congress shall make no law respecting an establishment of religion, or prohibiting the free exercise thereof; or abridging the freedom of speech, or of the press; or the right of the people peaceably to assemble, and to petition the Government for a redress of grievances."
The key word here is "Congress." This law - and it is a law - applies to the Federal Government. It is illegal for the Federal Government - and specifically Congress - to make any law, or for law enforcement to attempt to enforce any law, that abridges (deprives, cuts off) freedom of speech. It is not, however, illegal or a violation of civil or human rights for a private enterprise to protect their own interests and/or the interests of their subscriber/customer base to limit speech to that which the private enterprise deems appropriate. On a forum owned by a private company, the Bill of Rights - specifically, the First Amendment - does not apply because the law was written to specifically prevent the government from denying the people the right to express themselves freely. It was not written, and is not intended to, prevent private companies whose business is communication from developing and enforcing policies and standards of conduct.
Hope this helps clear that up a bit.