Online Service Providers (OSPs)—such as AOL, Facebook, Google, Microsoft, and Twitter—are increasingly expected to act as good citizens, by aligning their goals with the needs of societies, supporting the rights of their users (Madelin 2011; Taddeo and Floridi 2015), and performing their tasks according to “principles of efficiency, justice, fairness, and respect of current social and cultural values” (McQuail 1992, 47). These expectations raise questions as to what kind of responsibilities OSPs should bear, and which ethical principles should guide their actions. Addressing these questions is a crucial step to understand and shape the role of OSPs in mature information societies (Floridi 2016). Without a clear understanding of their responsibilities, we risk ascribing to OSPs a role that is either too powerful or too little independent. The FBI vs. Apple case,1 Google’s and Yahoo!’s experiences in China,2 or the involvement of OSPs within the NSA’s PRISM program3 offer good examples of the case in point. However, defining OSPs’ responsibilities is challenging. Three aspects are particularly problematic: disentangling the implications of OSPs’ gatekeeping role in information societies; defining fundamental principles to guide OSPs’ conduct; and contextualising OSPs’ role within the broader changes brought about by the information revolution.