If speech is provably false and part of a pattern of disinformation designed to stir up hate and violence why is it a problem to police it? My opinion on that

If speech is provably false and part of a pattern of disinformation designed to stir up hate and violence why is it a problem to police it? My opinion on that is irrelevant because that isn't the topic of discussion. This comment chain regards d23's disagreement with my assertion that a significant fraction of the HN user base (like you) believe hate speech should be illegal. I'm not saying you're right or wrong; I'm just saying you exist on this website.