Well, there are two main things that come to mind. First, it cause diseases in people. Your eyesight will deteriorate as you look at your smartphone too much and use it in the dark. Also, your neck may bend or your back may deteriorate because you bow your head and look at your smartphone. In this case, watching music or videos using smartphones with wireless earphones may lead to poor hearing. Furthermore, because there is everything in the world or smartphones, there could be social problems that cause obesity and lead to lonesome people who prefer to stay alone. Second, it has a negative impact on people. In ohter words, people who encounter smartphones easily watch and heard fake news, which can cause disgust and lead to crimes by easily encountering violent and sour videos. In this case, it is children and teenagers who are severely affected. It is becoming an important social issue as the age of access to smartphones is getting younger and younger around the world.