This article sheds light on a challenge to the emancipatory potential of social media for social movements that has so far largely been overlooked: corporations’ monitoring of individuals. In this way, it goes beyond the ways in which corporations draw on ‘big data’ from online sources and instead explores how they (1) monitor and (2) discuss strategies for responding to the activities of individual activists, specifically in social media. Theoretically, it draws on Thompson’s concept of mediated visibility, Mouffe’s concept of the (post)political and Carpentier’s notion of the fantasy of the post-political. Empirically, it focuses on the oil industry and the climate justice movement in the United Kingdom. Here, it draws on files from British Petroleum (BP) and Shell on specific individuals obtained through Subject Access Requests under the Data Protection Act as well as press responses from the two oil companies.