"A recent study found that teenagers spend as much as nine hours a day in front of various types of screens. What impact is all that electronic input having? This book examines the many ways in which social media in particular, and the internet in general, can affect our health, both mental and physical. Online safety, privacy, and dealing with cyberbullies are all discussed. The goal is to make sure that we use social media, rather than letting social media use us"--Back cover.