In the article, the peculiarities of the communication activity of Russian social movements in organizing online and offline actions are explored on the example of the conflict between the authorities and the public concerning the official decision on the transfer of St. Isaac’s Cathedral in St. Petersburg (in the building of which the museum works) to the Russian Orthodox Church. As a theoretical and methodological basis of the study, a modernized theory of social movements is used, taking into account their features associated with their use of new communicative capabilities of social networks. Methods of dynamic network analysis were used for analyzing the collected empirical data on the content of the political communication of the network groups. The structural characteristics of the online communication of the two protest network groups “Let’s protect…” and “Let’s save…” the cathedral museum as well as communication links between them are revealed. The differences in their chosen strategies of fighting against the government’s decision are illustrated. The stages of their development are emphasized: mobilization of the movement’s participants by cultural figures and politicians dissatisfied with the decision (January 2017); organizational institutionalization during meetings and rallies (February — May 2017); attainment of the goal (June 2017) with the subsequent termination of the decision (success of the movement). The dynamics of the volume and structure of communication during the entire period of the conflict are analyzed at each stage. A conclusion is made about the real political power of the e-movement during the conflict. It is proved that the use of social networks does not automatically result in the success of the network protest movement, much depends on the chosen strategy. Network protest mobilization alone does not ensure the success of the movement in Russia.