This article presents a set of grounded hypotheses on the relationship between communication and power relationships in the technological context that characterizes the network society. Based on a selected body of communication literature, and of a number of case studies and examples, it argues that the media have become the social space where power is decided. It shows the direct link between politics, media politics, the politics of scandal, and the crisis of political legitimacy in a global perspective. It also puts forward the notion that the development of interactive, horizontal networks of communication has induced the rise of a new form of communication, mass self-communication, over the Internet and wireless communication networks. Under these conditions, insurgent politics and social movements are able to intervene more decisively in the new communication space. However, corporate media and mainstream politics have also invested in this new communication space. As a result of these processes, mass media and horizontal communication networks are converging. The net outcome of this evolution is a historical shift of the public sphere from the institutional realm to the new communication space.