Exposure to political disagreement has been shown to affect individual attitudes and behaviors in multiple ways. Past research has studied multiple sources for encountering diverse perspectives on controversial issues. Some work has also explored the possibilities and risks of internet use in promoting or restricting exposure to opposing stances on online forums and other spheres, analyzing relationships between media consumption and political attitudes, knowledge, and some forms of political activity. This research brings together two areas that have been understudied: the relationship between internet use and higher threshold political activities such as protesting as well as the connection between website content and network structures with participant attitudes. It argues that protest mobilization processes provide different levels of bridging between political divides as protest conveyors need to counter-argue adversarial arguments and frames and this makes them an important source of exposure to political disagreement. As social movements and other civil society organizations play a role in mobilizing political action they are becoming central actors in capturing attention online for politically interested individuals who trust their brokerage functions in an increasingly intricate electronic public sphere. Network analysis of issue actors online for three protest events in Spain and surveys of participants at those events provide evidence to analyze the extent to which cross-connections between opposing stances are significant factors for explaining differences in protest participants’ attitudes such as perspective taking.