•Along with the health problems caused by the excessive use of cell phones, parents should be concerned about how teenagers use cell phones. It is not a secret that adolescent subculture is strongly based on hierarchy; those who do not manage to fit in often become bullied by their more fortunate peers. In these terms, cell phones provide limitless opportunities for what is called cyber-bullying. For example, camera phones can be secretly used almost anywhere, including private areas (such as restrooms and locker rooms), where bullies can take embarrassing photos of their victims; then, using their cell phones, bullies can spread these photos around school in no time, upload them to YouTube, or publicly humiliate their victims in some other way. This is not to mention sexual harassment (apps like SnapChat make it easy), digital revenge for broken relationships, hacking and stalking, and so on (Safe Search Kids). It is impossible to control a student outside of school, but doing this during classes is not difficult.