Ok so here's my question again: how do you ensure that limits on unwanted speech don't come back to bite you in the ass?
Like, now you get to decide which speech is allowed, but what happens when your neighbor gets the stick?
We can't ensure that. whether we're talking about government censorship or facebook's latest policy. And that's a problem. But we should look at those risks as a realistic balance sheet rather than a deal breaker.
And let me clarify that I'm not even necessarily talking about government enforced censorship. I'm more saying that a faith in the marketplace of ideas and the sanctity of free speech shouldn't stop us from realistically looking at the pros and cons of how we deal with speech in lots of settings, including the rules of online message boards.
When electricity was rising in popularity, opponents of the new technology came forward with some serious risks. It could burn down a house! People could be electrocuted! etc etc. All of their risks were real, but we find that we prefer living with electricity and all that it makes possible and living with some level of those risks.
So let's look realistically at the risks of abuse of limits on speech.
For one thing, I don't think speech is really that different from other actions.
We limit people's motion in a million ways from jaywalking laws to private property protections. We limit the things you can own- you can't have a nuclear bomb or a million species of wild animals. We limit what you can build- you can't build a house that doesn't meet regulations etc etc etc.
And yet, we're not that concerned that allowing the general principles of regulation in all those areas is such a slippery slope that we'd better not go there at all.
And really we're not entirely virginal on limiting speech. We've had obscenity laws forever. We have laws about truth in advertising (and that often difficult concept of "truth" can be it's own slippery slope). We have defamation law. We consider some utterances harrassment or threats.
And we don't have to look to dystopian counterfactuals to imagine what might happen with stricter speech controls than we have in the US. Germany makes it illegal to deny the Holocaust or praise Hitler. The UK has has stricter regulation of speech on a number of grounds. Both have had such policies for a while and haven't become apocalyptic hellholes. They may have some government action that some people here don't like, but they haven't slid down those slopes yet. They may not really be so slippery.
To some people, free speech is an end in itself. I don't hold that value, I don't think free speech is much different than freedom of movement. If we can handle crosswalks and traffic laws, we can probably survive making it uncool to be a Nazi.