People act differently when alone and when in mobs of like-minded people.
We have fear and anger as individuals, but rational fear of consequences usually prevents us from acting violently individually.
In mobs, however, we often become irrational, divisive, destructive. The solidarity of like-minded people reduces fear and reinforces anger. It incites us, and we are much more likely to engage in mindless violence that we may later regret -- if only for being punched back or being convicted of violent crimes.
Unfortunately, social media now allow us to form virtual mobs that reinforce our anger and encourage us to act violently as individuals or come together more readily to engage in mob violence.
If authorities don't confront these thugs vigorously, they'll progress to lynch mobs with human victims on every side.
Hate and violence stimulate hate and violence from other sides, and the cycle of hate and violence escalates.
Hateful words and demonstrations are properly protected by the First Amendment. Fascist Nazis, fascist communists, white racists, black racists, anti-Semites, fascist antifa and other mobs that receive (and they must receive) permits to demonstrate nonviolently have that right.
But there's no right to vigilante violence. Any mob harassing anyone or initiating violence anywhere, including against legally demonstrating nonviolent mobs or police, is responsible for the consequences.
Don't hate. Don't harass. Don't initiate violence.
Don't join or surrender to mobs.
They're mindless, become heartless, then vicious.