These threats are real.
The weaponization of everything is actually happening. Since I wrote about it a month ago (Self-Crashing Cars) a number of people have reached out including people with actual insight into the military aspect of it. Militaries around the world are getting ready for true AI enabled weapon systems and there building deterrence strategies for mass casualty cyber attack (including nuclear weapons response), whether its from hacked industrial plants or cars it doesn't matter. They're actually talking about the weaponization of cars at the Munich security conference.
We need to stop burying our head in the sand and write to our politicians about this threat. I know it sounds crazy but it's real.
As an aside, my main complaint about the people that truly understand this the inability / unwillingness to accept that the act of subverting systems capable of mass destruction via cyber attack amounts to cyber weapons of mass destruction. We need to assemble all the work / treaties / regulations / research we put into securing nukes into securing AI / robotics and for the identical reasons. We know how this ends otherwise. We need wide-spread government funding and we need to communicate what these things are in language that our governments understand. Not saying something that is true just because it sounds weird is counterproductive.