Interesting point, though I wouldn't say that censorship engenders violence; in the same way, you point out that hate speech doesn't necessarily result in violence. Both create the conditions for the possibility of violent acts: censorship enables a violent state, hate speech incites a mob. That was more pithy, but were I to attempt to be more accurate in the cases we're discussing: hate speech incites individuals, whose symbolic violence is appropriated and exploited by a mob.

More to the point, I don't think genocide is what we're primarily concerned with. I have no statistics- so I forward this tentatively- but I wouldn't describe the Southern US as laden in "large scale acts of violence" during the early 20th century. To my knowledge, there was nothing that could properly be termed genocide. What *did* exist was a culture that used violence against individuals to imply a threat against a group. Organizations also staged demonstrations to ensure that such threats were clearly understood and broadened beyond that incident.

I expect we find the same thing objectionable, but I seem less confident in my solutions. In its effect, hate speech censors the group it targets. Both censorship and hate speech, ironically, appropriate power from the vulnerable, exploiting the society in a pretty cynical way. Censorship takes the responsibility to protect the citizenry- and uses it to weaken it- while hate speech takes the society's openness- and uses it to silence others.

I don't know what is to be done.