Materials for making decent explosives are usually controlled. If you're talking homemade explosives, you probably aren't getting that on a quadrotor, or if you

Materials for making decent explosives are usually controlled. If you're talking homemade explosives, you probably aren't getting that on a quadrotor, or if you are, you're seriously compromising its performance. Bullets are controlled through licensing in most first world countries. If you wanted to control components going into homebuilt drones, you would probably target the guidance, since even basic waypoint navigation requires something to tell you where you are in relation to the target. To an extent this is already done with GPS (the true precision was classified last I checked, civilian uses are downgraded), but controlling manufacture and distribution of the stack would shut any kind of home robotics down while leaving a lot of channels untouched. If people wanted PCBs, fine, they just wouldn't be able to get certain sensors on them without a license. You don't need global DRM to control exports. It's routine for some industries. Of course, much of this is besides the point, because if someone really wants to hurt other people, they'll find a way. But the components to build a cruise missile in your backyard not only exist, they're mostly available COTS, but the critical parts like the payload are controlled. In some hypothetical future where AI drones became a threat, you can bet that the critical paths would be identified fairly quickly and locked down.