Based on political struggle around the handover of the St. Isaac’s Cathedral in St. Petersburg (which functions as a museum), the authors investigate cultural and political specifics of the public movements in large cities and give an attempt to assess the impact that the online communications have on the success of those movements. Social movement theory and Luhmann concept of communication are used to provide a full analysis of participants’ mobilization on the Internet. The authors use big data analysis along with questionnaire survey instrument to collect empirical data related to network political communications and traditional political activities in support for or against decisions. The study explores socio-structural and so-cio-political features of the groups, their connections, a relationship between online communication intensity and traditional political actions such as rallies or marching in support for (or against) political decisions. The case study helps to describe how the given cultural and political movement shapes the final decision. It is proved that the use of social media increases the influence of protest movement on decision-making but in Russia this is not an alternative to traditional political protest.