When I was a restaurant manager, employees were required by the company to pull back and pin their hair, also they had to wear hairnets (my preference) or a hat. One guy thought he would get around that rule by shaving his head, guess what, he still had to wear a net! lol It seemed that new employees would try to rebel a couple times, but after getting reprimanded, and their hours cut, most came around. Otherwise, they were let go.
Now, I work in a factory making windshield wipers. Our plant manager believes (incorrectly) that a hair can short out the systems, so here I am wearing a hairnet again! If those employees I reprimanded knew, they'd be laughing their heads off!!