They make them or 3D print them, the jet engines can put out up to 40 pounds of thrust and ya could make a small cruise missile from a couple. So ya can see why they are restricting things a bit, when someone could order parts and shit online and make a cruise missile in their garage. It might not be as big and fancy as Uncle Sam's, but it will get the job done in most cases and could hit a target with GPS from many miles away at close to tree top level. Shit you can even implement scene imaging and comparing technology for navigation today with little difficulty and the thing could even terrain follow to a degree.