This article presents a study of how politically engaged young people use social media for political purposes. There has been a growing optimism that social media can stimulate political participation and deliberation, especially among young people. Based on focus group interviews with Norwegian teenagers, the article argues that social media have become an important platform for young people to participate in political activities. Whether the purpose is internal meetings or external mobilization, social media provide platforms for planning, reporting and communicating political activities. At the same time, politically engaged young people are hesitant about using social media for political deliberation. They are concerned about how they present themselves, and they are reluctant to stand out as highly political. One important explanation for this is that social media integrate different forms of communication and collapse social contexts. This causes teenagers to delimit controversies and try to keep political discussions to groups with more segregated audiences.