Most of the drivers, however, had the sense to stay put,...

Most of the drivers, however, had the sense to stay put, fuming behind their blank windshields as they calculated the cost of repairs and repainting. Practically all of them were armed, but not one was stupid enough to pull a gun. It had been tried during a Trainite demonstration in San Francisco last month. A girl had been shot dead. Others, anonymous in whole-head masks and drab mock-homespun clothing, had dragged the killer from his car and used the same violent acid they applied to glass to write MURDERER on his flesh.
In any case, there was little future in rolling down a window to curse the demonstrators. Throats didn't last long in the raw air.

John Brunner

December A ROOST FOR CHICKENS - The Sheep Look Up (1972)