text: One of the less common ones that happen during school is emergencies. Let's say there's a bomb threat. They have no idea where the bomb is, or where it could possibly be, so they move all the students and teachers to another building, or they wait outside. That would be a bad situation if you weren't allowed to have your cell phone. You could easily call or text your mom asking to come pick you up (if the school allows it, that is) and that conflict would be resolved while you're not there, and not in danger. The only reason that would be a problem is that when the police are on their way to investigate, they would have a hard time getting into the school while the parents are on their way to go pick up their kid.