Earlier this summer, a Connecticut man rigged a handgun to the top of an unmanned aircraft, posting a video of the device hovering in the woods and firing shots. The spectacle raised more concern about how consumers or law enforcement could wreak havoc with drones, a fast-growing technology with immense potential. The leading drone industry group, the Federal Aviation Administration (FAA) and some law enforcement groups have spoken out against equipping the unmanned devices with weapons.