Self-driving car bombs?

Are we looking at a future where any hateful person could easily convert a self-driving vehicle into a car bomb? In an America that is becoming increasingly factionalized and hateful, wouldn't this threaten to destabilize society? Should self-driving vehicles be banned? Think about a self-driving tractor-trailer loaded with ammonium nitrate soaked with fuel oil. I am certain there are people in America who would find detonating one attractive. What sort of targets would be attractive to such people? Even a SUV could be devastating.