When I say I am in favor of free speech, I mean I do not want my government to make certain printed combinations of letters illegal or forbidden in all contexts. I don’t really care what private citizens say/forbid, just don't ban any books. If you want to ban Controversial Speaker X from your humble saloon/opera house/college because their followers tend to cause expensive damage, I don't blame you in the slightest -- just don't send them off to some gulag, or try to silence them permanently.
Free speech was a lefty thing when I was growing up. It had to do with comedians being able to use naughty language (see Lenny Bruce, George Carlin) and filmmakers being able to show boobies. Once these things were allowed they swiftly became ubiquitous and censorship shifted to the right.
Now freedom of speech is a righty thing, and it seems to be mainly concerned with insulting others. Many of my fellow liberals seriously believe that you can eradicate prejudice by banning insult words; I don’t agree with that. I do agree that speech can be used to whip crowds into frenzies, and that frenzied crowds have been known to kill people. In fact, one of the main complaints liberals tend to make about conservatives is their penchant for getting all riled up and killing people, and I think it’s a very valid complaint.
However, the whole issue of weaponized words is slippery. Especially if you take into account the wounds suffered by narcissists whenever someone abuses them with language like, “That’s incorrect” or “I only like you as a friend.” It’s easy to tell when hate speech has gotten people riled up to the point of violence, because there are corpses and/or bloodstains, but it’s really hard to tell where that point is, and how far you can go before reaching it. When you're uncertain, it's always best to err on the side of fewer corpses/bloodstains. Always. Beating human hearts outrank rhetorical discussions every single time. If the public wishes to keep the kind of speech that incites violence out of their public forums, it's no different from a private individual kicking an abusive drunk out of their party. And to understand where the limits lie, you need to take aggression into account.
Now I have piles upon piles of opinions regarding aggression, and to my mind a lot of the culture wars have to do with aggression displays and social appropriateness thereof (only female forms of aggression are allowed? only upperclass forms of aggression?), and I think aggression is to our culture what sex was to the Victorians. An aggressive person might get in your face and growl “I love you” and terrify you; a loving person might call you obscene words and make you want to marry them and live with them forever.
I really think we need to sit down and talk about aggression. Aggression is not violence, nor is it innately sinful, and you can’t train it out of people. You can handle it responsibly by directing it against game opponents, tennis balls, business goals and such. If we’re ever going to have that talk we will need to use our words.
That’s why it’s a bad idea to go around banning words. Only a lubberwort would do that.
[“Lubberwort” is an archaic insult. Once it fell out of fashion, people didn’t stop insulting each other. They just made up new insults. If you take away words and everyone has to make up new ones, it doesn't stop conversation so much as slow it down.]
EDIT: That kind of rambled … TLDR: While the gov’t shouldn’t ban books/people it is under absolutely no obligation to give them a forum. Also, we humans need to understand aggression better so we can discuss sensitive matters more constructively, and I’m as guilty of screwing this part up as anyone else. It's not the words and syllables that cause the harm, it's the aggression, and banning words won't solve anything at all.