This article proposes to analyze, based on the theory of social movements, the mobilizations that obtained attention in June 2013 in Brazil. Based on the observation of protest activities in the city of Santa Maria, in the central region of Rio Grande do Sul, it examines their development, evaluation and consequences in Facebook, as a means to gain an overall understanding of the role of online social networks within the logic of contemporary social movements. Interviews with protests participants were combined with online and offline strategic observations. The analysis indicates a discussion on how Facebook is used to construct  a plural agenda of demands, to reflect upon forms of action, articulate exchanges between opposites, to create a sense of belonging and a link between subjects with different opinions, as well as to build dynamic interaction and visibility for the protest activities. This particular situation requires reconsidering the theoretical field on social movements.