“but when the allowance of “free” speech incites violence it should be banned.”
No... the violence should be banned. Or the people participating in the violence. It’s the violence that is the problem, not the free speech.
Suppose we said freedom of religion was OK except when it pissed the majority off... Then the religion should be banned.
By their own standards, islam itself could be outlawed because so many of its followers kill in the name of islam.