Enemies of the state in hostile countries, that's been standard policy for nearly as long as drones have existed. It's a new and improved form of assassination which is used for the same kind of things assassination has always been used for.
Petty criminals are another story entirely. We could easily let human officers fire at will if we supported it as a society, but we don't, so automating that is not a natural step forward.
On the other hand, simply using the recognition side of the equation is a more slippery slope. Wanted posters have been accepted for centuries, so this is in many ways just an improvement on what police already do. But just because something is accepted as a necessary evil doesn't mean that it is still acceptable at orders of magnitude greater efficiency.
Petty criminals are another story entirely. We could easily let human officers fire at will if we supported it as a society, but we don't, so automating that is not a natural step forward.
On the other hand, simply using the recognition side of the equation is a more slippery slope. Wanted posters have been accepted for centuries, so this is in many ways just an improvement on what police already do. But just because something is accepted as a necessary evil doesn't mean that it is still acceptable at orders of magnitude greater efficiency.