The political online communication of young participants in unauthorized protests in Russian megacities is especially interesting for Russian scientists. It allows identifying priority forms of protest political participation of young people online and offline. The report shows the results of a study of the political online mobilization of youth from million-plus cities (early 2021). The study was carried out using the methods of mass online survey of young people, an expert survey (the method of non-standardized interviews) and analysis of youth political Internet communities on VKontakte, Twitter and Telegram. The results obtained allow us to predict the potential of youth protest participation in public unauthorized actions in the coming months. They are valuable material for political strategists working with youth, representatives of government bodies and civil society institutions. The research carried out destroys many false stereotypes regarding the mass consciousness and behavior of politically active youth.