He belonged to a band in Niterói, a Brazilian city surrounded by beaches, and practiced playing the guitar by watching online tutorials. YouTube had recently introduced a new artificial intelligence system that learned from user behavior and suggested videos based on that. One day, he came across a video by an amateur guitar teacher named Nando Moura, who had gained popularity by sharing videos on heavy metal, video games, and politics, particularly expressing far-right views. Intrigued, he started watching more videos from Moura and other far-right figures recommended by YouTube. One of them was Jair Bolsonaro, who was a relatively unknown politician at the time but had a significant following on YouTube. Eventually, Bolsonaro became the President of Brazil. YouTube became a prominent platform for the far-right in Brazil, influencing the political views of people like Matheus Dominguez, who is now 17 years old and considering a future in politics. YouTube has thrived by keeping users engaged, but this has inadvertently benefited extremist groups. A study in the company's second-largest market revealed significant negative impacts. In Brazil, the far-right movement has gained momentum thanks to YouTube's recommendation system, which directs users towards extremist and conspiracy content. This has disrupted everyday life, with students quoting conspiracy videos in classrooms and parents receiving harmful health advice from the platform. The influence of YouTube on Brazil's society has been profound and concerning. Viral videos have led to death threats against public health advocates, while right-wing YouTube stars have entered politics alongside Bolsonaro, with some winning by large margins. These stars continue to use the platform to govern a major democracy through trolling and provocation. YouTube's recommendation system aims to increase watchtime but claims not to favor any political ideology. However, experts warn that the system's promotion of provocative content can lead users towards extreme views, including right-wing extremism. This system now accounts for 70% of total time on the platform, generating over $1 billion a month in revenue. Some analysts believe that YouTube is one of the most powerful tools for radicalization in the 21st century, though company representatives deny this claim. However, representatives of the company acknowledged some of the findings and promised to implement changes. Farshad Shadloo, a spokesperson for YouTube, stated that the platform has made significant investments in policies, resources, and products to combat the spread of harmful misinformation. He also mentioned that authoritative content is thriving in Brazil and is highly recommended on the site. Danah Boyd, the founder of Data & Society, attributed the disruption in Brazil to YouTube's strong push for viewer engagement and the revenue it generates. Despite Brazil's previous challenges, Boyd expressed concern over YouTube's increasing influence on democracies globally. Maurício Martins, the local vice president of Bolsonaro's party in Niterói, credited YouTube for recruiting many party members, including himself. He explained that he was introduced to right-wing content on YouTube, which served as his political education. The platform's political impact is also evident in Brazilian schools, where students are exposed to extremist views through YouTube stars like Moura. Carlos Jordy, a City Council member, rose to prominence by focusing on YouTube and accusing local teachers of communist indoctrination. The individual credited his rise to the federal legislature to the national audience he gained from his videos. He believes that without social media, he and Jair Bolsonaro would not have reached their current positions. A team of researchers at the Federal University of Minas Gerais analyzed YouTube content in Brazil and found that right-wing channels were growing faster and influencing the site's political content. Positive mentions of Bolsonaro increased after YouTube changed its algorithm, even though he was initially unpopular. Researchers at Harvard's Berkman Klein Center investigated whether YouTube's recommendation engine contributed to the Brazilian far right's rapid growth on the platform. They programmed a server to explore top recommendations and track how users moved from one video to the next. They discovered that following the viewing of a video on politics or entertainment, YouTube's recommendations tended to promote right-wing, conspiracy-driven channels like Moura's. Importantly, users who watched one far-right channel would often receive recommendations for many more. The researchers found that the algorithm had brought together previously marginalized channels and built an audience for them. One of these channels belonged to Bolsonaro, who had been using the platform to share hoaxes and conspiracy theories for a long time. Despite being an early adopter of YouTube, his online following had not significantly expanded his political base, which was almost non-existent on a national level. However, when Brazil's political system collapsed and YouTube's popularity surged, Bolsonaro's views remained the same but his audience on YouTube's far-right channels grew exponentially. This helped to prepare a large number of Brazilians for his message at a time when the country was ready for a political change. YouTube disputed the researchers' methodology and stated that their internal data contradicted the findings, but they declined to provide the data to the Times or certain statistics that would confirm the accuracy of the researchers' findings. Many Brazilians who turned to YouTube for health information were scared by videos claiming that Zika was being spread by vaccines or insecticides. These videos used alarming claims to captivate viewers, similar to extremist political content. Doctors and officials expressed concerns that these videos were causing a public health crisis by convincing people to refuse vaccines and insecticides, particularly in poorer areas like Maceió. Medical professionals were finding it difficult to combat misinformation spread on social media platforms like YouTube, leading to a resurgence of diseases like Zika in some communities. The Harvard researchers discovered that YouTube's algorithms often steered users searching for information on Zika, or those watching credible health videos, towards conspiracy channels. A spokesperson for YouTube acknowledged the findings and stated they were unintentional, and that the company would be adjusting how search results related to Zika were displayed. This phenomenon was described as an 'Ecosystem of Hate', where far-right figures used conspiracy videos to target individuals for blame. Conspiracy theorists on YouTube accused women's rights activist Debora Diniz of involvement in alleged Zika plots, suggesting that those working to assist Zika-affected families were actually behind the disease. As far-right and conspiracy channels began referencing each other, YouTube's recommendation system started linking their videos together, creating the appearance of multiple sources corroborating the same false narrative. Diniz received threats of violence, including mentions of her daily routine, as a result of these conspiracy theories. Many statements from Küster's videos were repeated, she mentioned. Küster talked about the threats with excitement, but never directly supported them, which allowed him to stay within YouTube's guidelines. When Diniz's university received a warning of a potential shooting and the police could no longer ensure her safety, she left Brazil. Diniz expressed that the YouTube recommendation system has created a hateful environment, where viewers are exposed to a continuous loop of negative content. She emphasized the importance of holding companies accountable for their influence. From an ethical standpoint, they are accountable. As conspiracy theories circulate on YouTube, creators of videos are targeting aid organizations that deal with controversial topics such as abortion. Even families who have relied on these groups in the past are starting to question the validity of the videos and are choosing to avoid them. In Brazil, this behavior is referred to as "linchamento" or lynching. Bolsonaro was an early adopter of this practice, sharing videos in 2012 that falsely accused left-wing academics of planning to distribute "gay kits" in schools to convert children to homosexuality. Jordy, a protege of Bolsonaro from Niterói with tattoos, was not bothered to hear that his own YouTube campaign, which accused teachers of promoting communism, had caused turmoil in their lives. One of the teachers, Valeria Borges, mentioned that she and her colleagues had been inundated with hateful messages, creating an atmosphere of fear. Jordy did not deny this, stating that causing fear was his intention. He explained that they were engaged in a cultural war and that was his purpose for entering office. The epicenter of political influence through YouTube may be the headquarters of Movimento Brasil Livre in São Paulo, which was established to advocate for the impeachment of left-wing President Dilma Rousseff in 2016. The group's members are typically young, middle-class, right-wing, and highly active online. Renan Santos, the national coordinator, pointed to a door labeled "the YouTube Division" as the central hub of their activities. Inside, a group of young men were working on editing software, with one focusing on an image of Benito Mussolini to argue that fascism was wrongly attributed to the right. Despite their dedication to social media, some members are concerned about its impact on democracy. Santos referred to social media as a "weapon" that could be misused by some individuals close to Bolsonaro. Co-founder Pedro D'Eyrot warned of the "dictatorship of the like," where reality is shaped by what goes viral. A recent YouTube video titled "1964" defended Brazil's military coup, influencing the views of individuals like Dominguez, who believed his teachers had exaggerated the horrors of military rule. On the other hand, history teacher Borges, who was targeted in the video, was reminded of the dark days of military rule, including curfews, disappearances, and police brutality. Despite the disturbing content on YouTube, individuals like Matheus Dominguez credit the platform with shifting their political views to the far right. YouTube's success has been built on retaining users' attention, which has inadvertently benefited extremist groups. An investigation in the company's second-largest market revealed significant repercussions of this practice.