Governments: Stifling human innovation and ingenuity since the Assyrian Empire.
If there are no laws against the construction and use of trap guns and other premises defense devices that may be extremely harmful or fatal to people with ill intent, imagine the kind of ingenuity that would exist today that would permanently put perps out of the 'reoffending risk' category...
Home break in by armed and masked thugs caught on smartphone by homeowner who is out of the premises and nobody else or pets are at home? One tap of a button closes all windows and doors and floods the entire house with CO2 gas held in beverage fountain tanks stored in the basement and delivered by tubes in ceiling. Then after 60 minutes, hit 'ATMOSPHERE FLUSH' to open windows and activate heat circulation fans to purge the gas and reintroduce fresh air. Anybody else wants to break in?