The motivated terrorist who is willing to do anything, except die, might be able to fashion a car bomb, put it in a self-driving car (which is not that far in our future) and dispatch it to the intended location, while watching everything unfold via a GPS link and cameras in the car.
There are other criminal advantages to the self-driving car as outlined in FBI: driverless cars could be used as bombs-on-wheels. And note at the end of the article they also list the advantages that accrue to law enforcement.
Here's the deal, technology advancements cannot be contained to just the uses that benefit individuals and society. The invention of the car led to faster getaways from bank robberies. The cellphone has been a boon to drug dealers and pedophiles. We have to take the bad with the good, and just as terrorists may employ asymmetric systems to do their dirty work, we will need to employ these same technologies to do ours.
