In 2012, 15-year-old students spent over two hours on line each day, on average across OECD countries. The most common online activities among 15-year-olds were browsing the Internet for fun and participating in social networks, with over 70% of students doing one of these every day or almost every day. Students who spent more than six hours per day on line outside of school were more likely to feel lonely at school, arrive late and perform at lower levels in mathematics. On average across OECD countries, 7% of students spend this much time on line during a typical weekday. Based on statistics like these, this issue of "PISA in Focus" concludes that a concerted effort by schools, parents and society can educate students as critical consumers of Internet services and electronic media, helping them to make informed choices and avoid harmful behaviours. Schools can raise awareness in families about the risks that children face on line and how to avoid them. And parents must help children to balance leisure uses of information and communications technology (ICT) with time for other recreational activities that do not involve screens, such as sports and, equally important, sleep.