Currently almost 99% of Italian teenagers own a smartphone and with it they can enter the world of the infosphere: this fact has profoundly changed the online habits of teenagers. The pedagogical literature grafted onto Media Education has highlighted the cognitive and relational opportunities favoured by smartphones and their use by adolescents. Which are today's adolescent's online media-practices? In which terms these practices have an impact on adolescents' socialisation? This contribution intends to explore these questions and focus attention on the ways in which these devices are managed by teenagers on a personal level, offering a descriptive picture of the media practices activated in the context of the reticular society for the school and family context and consequent reflections on identity and on the sociability of adolescents. The research involved nine upper secondary schools with different curricula in the Metropolitan City of Bologna (1657 students, age 14-19) in school year 2020/2021. The data collected through questionnaires and focus groups highlight how technologies and social media play a role of fundamental importance not only as daily mediators in the relationships of young adolescents but also as a space for negotiation of their identity. And this role was crucial for their well-being during periods of lockdown due to COVID-19.