From a recent article in Counterpunch
Professions are supposed to operate within an ethical code and exercise independent judgment. Doctors have a duty to prevent harm. Biologists and chemists should urge their colleagues in physics to take a greater role as to where their knowhow is leading this tormented world of ours before the blowback spills over into even more lethally indefensible chemical and biological attacks.
I doubt that the attacks will become chemical. It could happen but I'm not looking at that. I think there is a larger danger whenever enemies decide to stop trying to target obvious and well secured targets like NYC. Of course it would make for great bragging rights but are rarely successful. There are far more vulnerable places where a remote control car or helicopter could be quite a problem, particularly with web enables devices.
Anyway I have said it before, when warfare becomes detached from actual human risk, then warfare becomes that much more dangerous to the target and more likely to be started by those with the automated systems.