Australia was one of the first countries to make it compulsory to wear seat belts (in the early 1970's) and has continued down that path by making helmets compulsory, not only for motorcycles but also to ride your bicycle. And yes, they do enforce it, as you can see from the photo below which I took outside my company's Canberra office yesterday.
The libertarian in me says this is wrong. But that same voice also tells me that if this grown man decides not to wear a helmet, lands on his head and ends up a vegetable, I shouldn't have to pay his medical bills. Unfortunately that's not the world we live in. Taking that as a given, I think forcing him to wear a helmet is the lesser evil.
When this gets really hilarious though is when the 'perp' is ten years old!