Recent developments in communications technology have transformed how social movements might mobilize, and how they can organize their activities. This thesis explores some of the geographical consequences of the use of digital media for political activism. It does this by focusing on the transnationalization of protests. The aim is to analyse how movements with different organizational structures and political scopes are affected by their use of digital media. This is done with a specific focus on how digital media use influences or enables transnational modes of organization and activism. The thesis comprises four different case studies where each study examines a social movement with a specific organizational structure. There are, however, also important similarities between the movements. In each study, somewhat different perspectives and methodological approaches are used. Some of the methods used are semi-structured interviews, content analysis of written data (retrieved from Facebook as well as Twitter), and social network analysis. The analysis indicates that digital media do have a role in the transnationalization of protest. This role, however, differs depending on what type of social movement one studies. The organizational structure of social movements, together with their specific forms of digital media use, influences how the transnationalization of protests and movements is articulated and formed. In cases where a social movement has a hierarchical organizational structure, there is less transnationalization, whereas in social movements with a more non-hierarchical organizational structure one sees more transnationalization. The thesis concludes that the transnationalization of protests is affected by social movements’ organizational structure. The more decentralized the social movement, the more vibrant the transnational public. In order to explain how transnational social movements, using digital media, can emerge in cases where geographical distances might make such coalitions unlikely, the thesis introduces the notion of affectual proximity. This concept helps us understand how transnational social movements, connecting actors from all over the world, can emerge through digital media.