In the Saints Row series they're called kneecappers and I tried and uninstalled them because they caused too much mayhem. They also appear in the Spy Hunter 1983 coin-op video game

I remember seeing them on Speed Racer used by villains before seeing the chariot race version in Ben Hur.

IRL they're obviously a hazard and inappropriate in traffic where people are just trying to collaboratively get home. (And yes, traffic is a collective cooperative effort, and we see that as soon as someone gets antagonistic.)

But Americans imagine themselves rugged individualists, a component of capitalist propaganda, and like to show they're rebels with shit like rolling coal and truck nuts.

This totally looks like a FAFO moment that is going to turn into a regulatory statute.

Since it's not a firearm, I doubt courts or officials will be interested at all in pursuing second-amendment liberties over this. They seem not to care about knives or ninja gear, either.