I'm a teacher at a middle school and cell phones, while nice for adults and older adolescents are a royal pain the in the butt for teachers. Our policy is if we see it we take it and the parents can come and get it.
The argument from parents is that they need to contact their child at anytime. Sure I understand that, but all schools have a secretary or a principal who is supposed to rely emergency messages to the students for parents. I took away so many phones last year I have lost count. Boggles my mind. When my kid gets old enough to drive then he/she is old enough for a phone, or they can pay for it and get it a little sooner.