[NoMoreNicksLeft]

The converse would have to be true then, that the government has the legitimate power to intimidate people to not express their opinion. This does not seem like a legitimate power for government to have, but now I need to be careful whether I express it at all.

[krapp]

Laws against slander, libel, intimidation, conspiracy, perjury, etc are based upon the government's power to intimidate people from expressing opinions. It is a felony in the US to express the opinion that the President should be killed. Speech in the US has never been a free for all.

[AnthonyMouse]

Those are not opinions, they're provably false statements or threats. Conspiracy is essentially committing a crime as a group rather than an individual, and the statements are the evidence of the crime rather than the crime in itself.

The closest the government comes to prohibiting an opinion is copyright, but even then you can restate the opinion in your own words, and when an exact quote is necessary to make your point it's fair use specifically because it would otherwise violate free speech.