It's not just 15-year-olds trying to go to sneak off to parties that have this problem. I have friends, all of them female, who are in college and have their phones tracked by their parents, in addition to relentless calling and generally unhealthily obsessive behavior. None of them, living with their parents, were ever allowed to leave their house unsupervised, save for school. Most of them don't drink or behave frivolously, and they'd be fine working and buying their own phones, but having the ball and chain are usually requirements for maintaining contact with their family, having their tuition paid, and having a place to live outside of school. Sure, they could try to sever their ties with their parents, but they wouldn't be able to pay for their schools, be a successful student (which leads to all those lovely job opportunities), and might not even be able to provide for themselves (economy and all).
And don't assume all parents are rational actors. Not all of them are. And in the cases of my friends, most of their parents are physically abusive. Yes, some of them have contacted social services, but they still can't help them with the aforementioned problems.
I COMPLETELY UNDERSTAND where most of you are coming from. If I had a teenager, I'd want to know everything they were up to, as well. But tracking phones can easily become abusive for, especially girls, who are trying to break out of stereotypical roles and be independent. Tracking phones doesn't protect them from harm- it just helps oppress them. If you're worried about teenagers, there's an easy solution that my parents used all my life (and I am a /guy/)- you could just never let them leave the house. (To this day, I still haven't walked around my block.)
