Research on the policies and practices of mediation, valuation, and education on open data reveals that open data has struggled to find its place in the public space, but that it triggers fundamental questions about the role of data in the functioning of contemporary democracy. The public open data space is determined in places of negotiation and in unclear arrangements. The devices that allow access to these data respond more to a logic of administrative and economic governance than to democratic principles. Thus, for open data to participate in a form of reinvention of democracy in the context of big data, the informational and cognitive practices that allow the use of data require complex acculturation actions and the development of data literacy.