text: I think letting them use their phones would resist them from the temptations to hide using it. Whether they are allowed to or not they will still use their phones. They will just hide the fact that they are using them. If you don't let them use their phones. It would make it less cool to use their phone because everyone will be using them but if you say that they can't then they will just be more rebellious and try to use it without your knowledge. You could make consequences for misusing your phone.