Spontaneous was my bad choice of words. Basically the guy was driving and found himself in the middle of a protest. He was trying to turn down a street to get away from it, but the protesters were storming into the street and surrounding cars--treating people who are trying to drive in the streets as if they are enemies--with one of them rushing up and pointing an AK at him. This goes far beyond protesting--they are threatening people trying to drive away with threats of violence at gunpoint. Rather than the protestors thinking, 'Hey, we are rushing into the street where people are driving and they might get scared and try to drive away," they seem to regard everyone outside of their group as enemies.