The enhanced discursive opportunity structures that the Internet enables has inspired a momentous revolution in the Nigerian media landscape. This dissertation chronicles the emergence and flowering of the citizen and alternative online journalism of the Nigerian diasporic public sphere located primarily in the United States. Using case-study research, it profiles the major diasporan online citizen media outlets and highlights instances where these geographically distant citizen media sites shaped and influenced both the national politics and policies of the homeland and the media practices of the domestic media formation. The study makes the case that while it is customary in the scholarship on sovereignty, state-civil society relations, and diaspora studies to emphasize domination and one-dimensionality in cultural flows, the participation of members of the Nigerian digital diaspora in the politics and discourses of their homeland, from their exilic locations in the West through the instrumentality of online citizen media, illustrates that citizens, especially in the age of the Internet, are not mere powerless subjects and receivers of informational flows from the institutions of the state and corporate mass media but can be active consumers and producers of informational resources and even purveyors of political power in ways that amply exemplify trans-local reciprocality. It also argues that the Nigerian diaspora media might very well be a prototype of an evolving, Internet-enabled, trans-local, and mutual informational and cultural exchange between the educated deterritorialized ethnoscapes of peripheral nations whose exile in the West endues them with symbolic and cultural capital and the private institutions and governments of their homelands. The study recommends a comparative study of the online citizen journalism of Third World virtual diasporas in the West.