Do people want to restrict 16 year olds with phones? That seems like a really bad idea. For 10 year olds it makes sense, but 16 is nearly adult; they need to really learn this responsibility. And of course they need a phone when they go out like these girls. A bit of a weird tangent from what apparently is harassment in a train or something like that? I admit it's hard to follow what is going on.
However, if a school district wants to restrict the use of smartphones during the school day for all students, I would be OK with that.