American high school teacher here (Midwest region). We implemented a policy this year banning cellphones in instructional spaces during instructional time. Enforceable by confiscation if teachers saw or heard a phone. We have a strong set of administrators who supported teachers in any case where there was student pushback. It has been a huge success in terms of limiting distractions during instructional time. All of our students are provided Chromebooks so there really isn’t much of an instructional reason to have phones anyway. It has also contributed to a drop in student-on-student behavior problems.

I do feel for the girl in this article for whom it was used as a coping mechanism for bullying. No policy comes with zero downsides. However, it sounds like she was allowed exceptions in certain cases, which is exactly what should happen.