I imagine it is illegal in this day and age to suggest the formation of vigilance committees but what are the good people to do when they get no protection from the government. With no redress, if the good people do nothing, it will lead to bad people doing something.
In Greece the “good people” would not respond to muslim violence so the Golden Dawn did. Now you have a facsist group that would normally recieve no support winning elections becuase they are seen by the average citizen as the only group pushing back against the foreigners.
Extrapolated to the US, if nothing is done about black violence against whites it will open the door for any group willing to use violence back to gain support, no matter their agenda. That will likely be a bad thing.
You said it. I also am worried about the police apparently doing nothing to protect good people. The liberals think they can prevent vigilantism by confiscating guns. Those of us who have actually picked up a history book know that acts of vigilantism have also been committed by knives, rope, torches, pitchforks, tar, and feathers. Are the liberals planning to ban those too?