The Cambridge Analytica scandal broke in March 2018. Several media outlets, including The Guardian, which had attempted to alert the public even before the US presidential election, revealed how the personal data of 87 million Facebook users had been collected and exploited by this company to promote Donald Trump. Conducted over several months by director Thomas Huchon, this investigation reveals a new aspect of the affair, detailing both how the data was used and the little-known role of the man who financed and orchestrated this massive manipulation: the ultra-conservative billionaire Robert Mercer, who heads the highly successful investment fund Renaissance Technologies. The man who bought the far-right website Breitbart News in 2012 also controls Cambridge Analytica, and decided to use both to impose his political agenda on the entire nation.