Abstract : The access to digital data is an economic, social and political issue. Accessibility does not only focus on the online publication of these data in a database, but as well in the discourses made by stakeholders on the web, such as the French association Regards citoyens. Since 2009, this group aggregates data of the activity of French Deputies in the French National Assembly, on the website nosdeputes.fr. In this case, political people allow the circulation of data that are arranged by actors without professional requirements unlike journalists. We are here interested in the enrichment of public data by citizens who participate in the public sphere in a form that differs from the mass media. We do not want to comment this public sphere but to describe it from the devices, the mediations that connect institutions and citizens. Therefore, we discuss the opportunity that a website like nosdeputes.fr can become the holder of a "digital public sphere" and interrogate the form of citizen oversight it induces. The frame of data on nosdeputes.fr questions the relationship between citizens, media and elected officials. On the one hand, these devices change the relationship between citizens and political action. On the other hand, we can assume that these devices bring politicians to adapt some of their practices in the French National Assembly according to the electoral agenda. We do not focus on the influence of some actors but on the oversight of citizens induced by this device. For example, nosdeputes.fr has listed activities of the 577 French Deputies since 2009. This survey provides detailed analysis of political activity in National Assembly but it is also interested in the look of the "citizen", by the comments he leaves on MPs' action.