IMO, a moral analysis of predator drones in a vacuum would probably find them morally questionable-HOWEVER-their targets are individuals who generally only attack innocent and defenseless civilians-and then retreat into the civilian population and hide among them. This is an abjectly IMMORAL form of warfare-if you can even call it that. Therefore, the use of predator drones to attack and kill those who kill innocent civilians and attempt to hide among them is inherently justified.