There will be no hard stats about this, and I do not know the soft stats. But civil liberty has been restricted on this point for years now in the UK, and it is very widely accepted to be a good thing even though racist deaths continue. It is a modification of our perfect bourgeois democracy in which a tiny measure of dictatorship is consciously exercised over reactionary elements. It is quite arguable.
Even the most pedantic civil libertarians admit there probably ought to be laws against maliciously shouting "Fire! Fire!" in a crowded cinema. If people are being assaulted and killed on a regular statistical basis what is the argument against controlling the fuelling of such ideas?
Chris Burford