Well, sure, but with major caveats. That quadrotor would never work, there's no way it could carry a machine gun and much ammunition with a battery powered motor. Not to mention the problems of recoil in a (relatively) frictionless environment, telemetry, etc. It would look a lot more like the MQ-8 firescout, which is a hell of a lot bigger/louder/expensive than that. A small drone like that carrying lethal weaponry and being effective is still a ways off.