Adam Liptak at the NYT has an interesting article about freedom of speech and how it's defined differently in various democratic countries. His thesis: in the US the freedom is basic, it includes the right to lie, offend and even preach hatred though not to incite to violence; in other countries where history has had its ugly chapters freedom of speech is sometimes curtailed so as to protect those societies from the proven worst in themselves; and in Canada, where there is no such troublesome past, freedom of speech is unabashedly curtailed so as to promote societal harmony.
While his pride at the American exceptionalism is probably justified, it might be worth adding that the very-non-free-speech ideology of political correctness is an American invention, also. PC isn't enshrined in the Constitution, thank God, nor will it ever be amended into it, one hopes, but it certainly reflects a powerful strand of American thought.
Personally, I'm all for more freedom, not less. I say this in spite of the fact that too much of the lying, offense and incitement to hate is directed against Jews, and always has been these past 2,000-some years. (And will continue to be). The Jew haters should be given the freedom to unveil themselves for what they are, so that we'll know to recognize them and protect ourselves, and also so that we'll be able to talk back so that their audiences also recognize them for what they are. Shutting them up won't make them go away, it will merely make them harder to find and combat.
My position, however, assumes a market place of freely expressed ideas, and the ability of people to think. The ability is there more often than not, I hope, but it shows itself only if there are competing ideas with which it can do its thing. When the spewing of hatred happens in sealed echo chambers where no other voices are allowed (i.e. where there is no freedom of speech), then the endless incitement surely is dangerous. Freedom of speech requires real freedom in order to work.
(This, by the way, was my motive for challenging that non-Arab who called himself Ibrahim, and then anyone else. I don't need them to shut up. I dare them to stand forward in a free and open market place, where their ideas can be cleansed by the sunlight of close inspection).