If you believe the press, both of those actually have happened. In any case, when you build a system reliant upon a software network, that network becomes a target. To say nothing of incompetence or corporate malfeasance to hide poor safety protocols. Blind faith in anything is dangerous. And autonomous vehicles are only the most recent example of that. We can distinguish the difference between a small child and a row of shrubbery. Autonomous vehicles can't. That makes a big difference when children do what children do and carelessly run out in the street.