My schools all banned cell phones from middle to high school. If one would go off or if you were caught by the teacher, they would confiscate it and you'd have to pay money to get it back by the end of the day. It was really funny watching kids covering each other no matter who you were if someone's phone went off in their backpack. We'd all start collectively coughing and making loud sounds to cover it up. Teachers for the most part were pretty relaxed on the phone going off in your backpack policy though. They only enforced the policy if you were caught using your phone during class.