Lots of dash cams in Russia, Eastern Europe and China. It keeps people from trying to lie their way out of accidents.
A guy had a helmet cam on here in MD when I first moved here. A plain clothes cop in a completely unmarked car pulled him over at gunpoint for speeding (not his job).
He apparently didn’t notice the helmet cam,, which was subsequently released on youtube.
As I recall, the officer was heavily admonished. Fired I think.
Had another incident where I didn't have one (and wish I had) as the situation almost took a bad turn based on an aggressive driver (not me) who thought he was in the right (he wasn't), and was willing to fight over it...
Good thing he never had to find out I was packing...