Share a scene in a movie/novel/tv show that is dystopic.

In the book Farenheit 451, the main character's wife is surrounded by four massive tv screens and she appears lifeless as she is engulfed into the tv wonderland.

Reasons are different for every school but the main reason would be because they can become a distraction and a problem for students. If a kid is playing on his phone in class then the teacher must stop the lesson to either take the phone away or tell the student to stop playing on it. Most schools I know allow phones in the school but if your school doesn't allow them they might just not want to have another thing to prevent kids from learning.