There's a whole sub-genre here of projects that would be (wisely) dismissed because they would land you in jail rather than their technical difficulty I suppose. I recall recently seeing a rocketry hobbyist realize their landing guidance tech is essentially the same as precision missile guidance and best not to make open source.
EDIT: I just remembered, it was Mark Rober's egg drop from space [1]
“A video appeared on the network shows russian soldiers disassembling the American-made Switchblade 600 suicide drone manufactured by AeroVironment. According to Bild, it is the first documented use of this drone by the Armed Forces of Ukraine.
Moreover, the drone is equipped with 3 “aero-naut CAM Carbon” folding propellers produced by German company Aero-naut Modellbau. It’s a German company that specializes in designing and manufacturing model airplane and boat kits, as well as model components such as electric motors, speed controllers, and propellers. But the company has stated that it never intended for its products to be used for military purposes, and has expressed concern over the use of its products in military applications without its knowledge or consent.”
EDIT: I just remembered, it was Mark Rober's egg drop from space [1]
[1] https://youtu.be/BYVZh5kqaFg