Hate speech is clearly not specific enough.
What must be prohibited is speech that jeopardizes the physical integrity of others. There must be a clear incitation to physical violence for it to not benefit the free speech label. Think Radio Mille Collines in Rwanda in 1994 for example.
https://en.wikipedia.org/wiki/Radio_T%C3%A9l%C3%A9vision_Libre_des_Mille_Collines