Free speech and burning theatres
With all the current brouhaha about Robert Kilroy-Silk and free speech, I'm surprised there hasn't been more reference to the dictum attributed to, I think, Justice Oliver Wendell-Holmes, that you don't have the right to shout "Fire!" in a crowded theatre when there isn't a fire.
I'm not so sure that this example really does represent a limitation on free speech. At least I don't think it can be used to justify state censorship. I would argue that is a consequence of the fact that you don't have a right to be in the theatre in the first place. You are only there with the owner's permission and he has every right to throw you out, or even sue you, if you breach the conditions under which he grants you that permission. But it does not imply that he, or anyone else, has any right to prevent you expressing your views in your own newspaper.
There is a big difference between state censorship and throwing an idiot out of your house. You may have a right to free speech. You just don't have the right to use someone else's property to exercise it.