The problem of risk and prevention of adolescents' risky behavior is one of the central issues in social pedagogy and psychology of personal health. Risk in these areas is understood as the probability of occurrence of negative consequences for health as a result of use of the Internet. The Internet actively fills the information space in all countries and is the basic means of creating the information society. The wide implementation of information technology in the life of adolescents has both positive and negative consequences. The negative aftereffects of the long-term use of information technology are narrowing the range of interests, escaping from reality in the virtual world and developing cyber dependence. At the biological level, adolescents are characterized by reactions of emancipation, association with peers and various hobbies that determine the search character of behavior and "tests of adult life." The mission of parents and social educators is to develop adequate forms of behavior, since ignorance and lack of social experience, the pressure of peers and friends can lead to risky (cyber-dependent) behavior. The paper deals with the essence, types, and characteristics of risky (cyber-dependent) behavior. Methods and forms of prevention of teenagers' risky behavior in the Global Network are analyzed as well. (C) 2017 Published by Future Academy www.FutureAcademy.org.UK