Contestations of truth standards have coincided with a decline of authority of established societal institutions such as science, government, courts, and the media. This triggered a self-reflective debate by science and technology studies scholars on whether their detailed descriptions of the networks of the techno-sciences, (de-)constructing facts and truths, contributed to this post-truth situation. This chapter explores a neglected counter-question to this debate, by symmetrically asking: What are the infrastructures for post-truth? How is fake news produced and distributed? It turns to empirical investigations of the Cambridge Analytica scandal around Brexit and the 2016 US presidential election, where disinformation touched the heart of democratic political institutions. It simultaneously focuses on the different sites, networks, and ICT technologies involved in the production and distribution of information, and on the actors engaged in exposing these networks involved in these controversies by tracking disinformation campaigns (investigative journalism, media studies, and data scientists). These also include traditional regulatory institutions reasserting themselves as sites for public dissections of these infrastructures. This controversy reveals a struggle for control of the median ICT infrastructures in the networked society. It provides insights in the attempts and counter-attempts of unscrewing the old sovereign state Leviathan, whereas simultaneously re-assembling techno-political new ones.