Your question as to Why blacks get away with attacks, statements graft, corruption etc.? The answer is simple people are afraid of blacks and their supporters. The slightest criticism and one loses ones livelihood. The cure is rough: ordinary political processes are no longer applicable.
Am I incorrect in saying that people that act like this (threats, intimidation, mob, riot) are terrorists?
By the very definition, it seems their actions are terroristic. I highly doubt the solution is political—conventional maybe....