If one terrorist attack is averted by tapping everyone's phone then it's worth it
While I agree that children should wear helmets, how are they going to enforce this law? Station a police officer at each resort? Have ski patrol detain the offender until a cop can come issue a citation? The first option is a horrible waste of manpower. Not to mention, do you really want a real cop stationed at your hill? If you walk by a (ski) patrol reeking of kind bud, none of us care, if you walk by a real cop reeking of bud...well you get it. The second is a waste of safety personal time. If I'm babysitting little Billy and his parents until a cop can get there, guess what, I'm not on the hill doing what I'm supposed to be doing. Which is keeping you safe, issuing first aid, and dragging you down the hill if you break yourself. So my time is better spent babysitting some brat rather then splinting your broken leg?
First of all, the cell phone tapping is entirely different - and for what it's worth, if tapping my cellphone would've stopped 9/11, then yes, tap my cell phone. Whatever I'm trying to hide isn't as important as saving people's lives.
And in regards to how to police this - it's very simple. You normally have someone stationed at the tops and bottoms of lifts right? Well, if someone gets off the lift and takes their helmet off, the operator at the top of the lift could easily radio down to the person at the bottom of the lift. When that rider gets down there, the lower lift operator can ask them to see ID if they're of questionable age, or otherwise tell them they can't get onto the lift until they've got a helmet on. It's pretty damn simple. Resorts would be able to enforce the rule pretty easily, and would need to since it's not just policy but law. If a minor was to get hurt on resort property without a helmet on, it could end up negatively for the resort.