I don't remember anyone in the USA ever wearing a hairnet except during a race, when helmets were required... a few guys had hardshell helmets in races too. Just out riding though, it was either hardshell or nothing.

I remember the rule book at the time said something like "helmets shall not be just useless straps of leather, they must have some padding to them"... LOL, obviously no testing standards to reference back then.

Helmets were also required in Belgian races when the rest of Europe didn't require them - so you can look at an old photo and tell that it was a Belgian race - this one is Het Volk I think.



As mentioned earlier, they do offer some protection against skidding abrasions... assuming they have some padding to them.