@RoboBlue:
There aren't large organized groups dedicated to racist violence, and I can't prove that there are small groups who are.
However, it's hard for me to wrap my head around the idea that a bunch of people just casually decided to take advantage of the chaos and start hunting down individuals based on their race without thinking it through beforehand.
This really isn't hard to imagine when you're part of a protest group and responsibility for taking it 'too far' won't land with you, but with the group as a whole. There's many sociological studies showing that if an actor is told that responsibility won't lie with them, but with a superior instead, human beings tend to completely lose track of moral boundaries for their actions.
There's always going to be a minority of people in any group that take it too far. However, I haven't seen much from BLM condemning it as 'too far'. Nor have I seen them take any action to prevent it from happening in future. I might be wrong (correct me if I am, if they've made it clear they're against this, if there has been an appropriate response), but I do think this tacit acceptance of racial violence that a minority of BLM supporters take part in (never encouraged, but never condemned), has a lot to do with why they are such a controversial organisation. That, quotas, and the tendency to see white people as a single entity, rather than a collection of individuals (all things that make me think twice before voicing support for them).
Nobody in their right mind wants police officers to target black people over white people. Nobody sensible wants black people to be sent to jail for crimes they didn't commit, or for petty crimes that a white person would get off scott free for (doing weed). Nobody wants black people to be overwhelmingly more likely to be shot by policemen. And BLM is right in standing for these things. It's just a pity they tarnish their reputation when people whom are part of the group voice hate for the white race or commit violence against white people solely due to their race, and seemingly do little to stop this behaviour.