The Samarco tailings dam broke on 5 November 2015, sending a wall of mud into the Bento Rodrigues township and killing 19 people. From there the mud made its way to the Rio Doce river system, killing fish and frogs, and causing massive pollution down to the mouth 650 km away. A year later a yellow fever outbreak occurred in the same state in Brazil, with 450 confirmed cases and about 150 deaths. After newspapers reported the yellow fever cases, online blogs started suggesting that the outbreak might have been caused by the Samarco disaster and citing comments by well-known scientists. Twelve months later another yellow fever outbreak occurred, and the online bloggers repeated the same claims, but the wording changed.In this paper we analyze the timing of the online activity, using Google search to find all the postings in the press and in social media with the two terms, “Samarco” and “Febre Amarela” (yellow fever, in Portuguese). In 2017, most postings faithfully reported what the scientists had said, but in 2018, some postings started making stronger claims than the scientists originally had. After analyzing the content of the postings, we construct two directed networks, one for 2017 and the other for 2018, to show to which scientists the postings refer and to illustrate the subtle and not so subtle distortions that started to creep in. In the conclusion we ask how the rise in hostility to mining expressed in some of these blogs should be interpreted. Is it just the usual low-level dislike of the extractive industries or are these the precursor symptoms of a more general refusal to accept mining in Brazil?