The internet most definitely does work with some restrictions on speech, pretty much everywhere worldwide has rules that limit freedom of speech to some extent. In some countries it's defamation, in others it's hate speech, etc, and it's no different in the US. Freedom of speech means you're protected from government censorship, not that you can freely say anything without consequence. For example, you can't publicly say that you will give X amount of money to anyone who will kill person Y, that's not what freedom of speech is about.