One Downside to Autonomous or Self-Driving Cars? Terrorism?

Hi folks -- I started looking at the history of self driving cars yesterday.  And it is a complex history going back to the 1920s when the first self driving cars were radio controlled. Of course, those early efforts were really remote controlled by an operator following the vehicle.  And as it turns out some of that technology goes back to developments that took place in the early 1920s at Wright-Patterson Air Force Base (then McCook Field).  The technology had its early roots, then, with the evolution of the aviation autopilot.

So much of more recent developments have a connection with DARPA and national defense initiatives. It is the idea of a robot car, a driverless car that one would employ on the battlefield. My big question related to the autonomous car is this:  what would keep terrorists from using them to pilot car bombs? Maybe this is all obvious to those involved in the development of the technology, but since I am a slow learner, I just thought of this and wonder.