Why do you think cellphones are banned in most schools? What consequence does this have for students?

Cell phone are banned in most school because children don't know how to act once hey have a cellphone in there hand. they get distract from cell phone and don't wanna do nothing in class , not paying attention cause them there learning for that day. these consequence the student have is not learning, distraction, they get caught up in the text-in, web searching & other stuff