Why? You can do what you want with your property, and what is more libertarian than property rights? Free speech is a contract between the government and its citizens. In an anarcho-capitalist society there is no government, only property, and what people choose to do with their own property. If someone doxed you, would you be ok if the mods refused to remove it because they didn't want to censor anyone? There's all kinds of stuff that should be censored: spam, scams, doxing, people accidentally revealing too much info about themselves, and anything that threatens the site's security or our security -- as a start. Personally I would censor that hate speech that occasionally pops up on the forum, but whatever, it's not my property.