This chapter focuses on how the forging of a new personal identity during adolescence plays out online, and the difficulties which adults (especially parents) have in understanding changes in children’s identities. It will start by looking at how teenagers express themselves visually using social media such as Instagram. Themes include changes in self-concept and self-esteem in adolescence, gender differences in online identity, the effects of Instagram use on body image, and the use of such visual media as emoji, selfies, and memes to form “private codes” for self-expression of identity within age-based peer groups, which adults can find hard to understand. Next, a major risk often cited by parents is examined, namely, the problem of “screen time”: how much is too much? This is relevant to the topic of identity because parents often feel like the internet has taken their child away from them, since due to identity changes they may prefer to spend time online with friends rather than face-to-face with families. I show that panic about widespread smartphone addiction is overblown, since screen time is not related with adolescents’ wellbeing across the general population. Nevertheless, I also argue that in extreme cases internet addiction can be a real problem. It is not the total time spent online that matters so much as the nature of the activities carried out online, and whether young people also have opportunities for rewarding activities offline. In this context, social networking software and smartphones offer new opportunities for clinicians to reach out to people at risk of mental health problems like depression and loneliness (both of which may be linked to changes in social identity during adolescence).