He was part of a band in Niterói, a Brazilian city surrounded by beaches, and practiced playing guitar by watching online tutorials. YouTube had recently implemented a new artificial intelligence system that learned from user behavior and recommended videos based on that. One day, he was led to an amateur guitar teacher named Nando Moura, who had gained popularity by posting videos about heavy metal, video games, and mostly politics. In his colorful and paranoid rants from the far-right, Moura accused feminists, teachers, and mainstream politicians of being part of huge conspiracies. This captivated him, and as he spent more time on the site, YouTube recommended videos from other far-right figures, including a lawmaker named Jair Bolsonaro, who was not well-known in national politics at the time but had a large following in YouTube's far-right community in Brazil. Bolsonaro was elected President the following year. Matheus Dominguez, who credits YouTube for influencing his shift towards far-right views, is now a 17-year-old considering a future in politics. YouTube's success in keeping users engaged has inadvertently helped extremist groups, according to a report in Brazil. The far right movement in the country credits YouTube's recommendation engine for their rapid rise to power. Recent research suggests that YouTube's search and recommendation algorithms have consistently directed users towards far-right and conspiracy theory content in Brazil. The New York Times investigation revealed that this has had serious consequences, disrupting daily life in various ways such as causing classroom disruptions, spreading dangerous health misinformation, and hindering public health efforts. Viral videos have led to death threats against public health advocates, and right-wing YouTube stars have entered politics alongside Bolsonaro, with some winning by large margins. These stars continue to use the platform to govern, using trolling and provocation. YouTube's recommendation system is designed to maximize watchtime and does not favor any political ideology, but can lead users towards extreme content. This has led to increased viewership and profits for YouTube, with some analysts estimating over $1 billion a month in revenue. Some experts believe that YouTube is a powerful tool for radicalization in the 21st century, while company representatives deny any bias towards extremism. However, representatives from the company acknowledged some of the findings and committed to making changes. Farshad Shadloo, a spokesperson, stated that YouTube has made significant investments in policies, resources, and products to reduce the spread of harmful misinformation, noting that authoritative content is thriving in Brazil and is highly recommended on the platform. Danah Boyd, founder of the think tank Data & Society, attributed the disruption in Brazil to YouTube's relentless pursuit of viewer engagement and the resulting revenue. Despite the existing corruption scandals and economic downturn in Brazil, which had already weakened the political establishment, Boyd expressed concern about YouTube's increasing impact on democracies worldwide, stating that this phenomenon is occurring globally. Maurício Martins, the local vice president of Bolsonaro's party in Niterói, credited YouTube for the recruitment of most party members, including himself. Martins described how he stumbled upon right-wing videos on the platform, which served as his political education and influenced his ideological beliefs. The platform's political influence is evident in Brazilian schools, where students are exposed to extremist views promoted by YouTube stars like Moura. Carlos Jordy, a City Council member, exemplifies the power of YouTube, as he turned to the platform for political inspiration and posted videos accusing local teachers of promoting communism. He stated that the videos helped him gain a large following and ultimately led to his quick rise to the federal legislature. He believed that without social media, he would not have achieved his current position. Researchers at the Federal University of Minas Gerais studied how YouTube influences its users' perceptions by analyzing transcripts and comments on videos. They discovered that right-wing channels in Brazil were gaining more viewers and influencing the site's political content. Positive mentions of Bolsonaro increased after YouTube altered its algorithm, even though he was initially unpopular. A team at Harvard's Berkman Klein Center investigated whether YouTube's recommendation engine had played a role in the far right's rapid growth in Brazil. They programmed a server to explore popular channels and search terms to track how users were directed from one video to the next. The researchers discovered that YouTube's recommendations tended to favor right-wing, conspiracy-filled channels like Moura's after users watched videos about politics or entertainment. Importantly, users who viewed one far-right channel would often be recommended many more. The algorithm brought together previously marginalized channels and helped them build a larger audience, according to the researchers. One of these channels belonged to Bolsonaro, who had been posting hoaxes and conspiracies on the platform for a long time. Despite being an early adopter of YouTube, his online following had not significantly expanded his political base, which was barely present at a national level. However, when Brazil's political system collapsed and YouTube's popularity in the country increased, Bolsonaro's views remained the same but his audience on the far-right of YouTube grew rapidly. This surge in viewership helped to prepare a large number of Brazilians for his message during a time when the country was ready for a political change. YouTube disputed the researchers' methodology and claimed that their internal data contradicted the findings, but the company refused to provide the data to the Times or disclose certain statistics that could confirm the accuracy of the researchers' findings. The spread of conspiracies on YouTube was not limited to politics. Numerous Brazilians who turned to YouTube for health information were alarmed by videos spreading false claims about the spread of Zika through vaccines and insecticides. These videos, reminiscent of extremist political content, instilled fear in viewers and led to a public health crisis as people refused vaccines and insecticides. The impact has been particularly severe in impoverished areas like Maceió, where residents were heavily affected by Zika. Medical professionals in Brazil expressed frustration at the influence of misinformation on platforms like YouTube, which has led to patients disregarding medical advice in favor of online sources. The prevalence of false information online has even caused a resurgence of the disease in some communities, indicating that social media platforms are currently wielding more power than the medical community in Brazil. The Harvard researchers discovered that YouTube's algorithms often directed users searching for information on Zika, or those watching reputable health videos, towards conspiracy channels. A YouTube spokesperson acknowledged the unintended findings and stated that the company would adjust how search results related to Zika are displayed. The rise of the far right led to conspiracy videos being weaponized, with leading voices using them to target individuals for blame. These videos accused activists like Debora Diniz of being involved in supposed Zika plots, suggesting they were behind the disease in order to push for the abolishment of Brazil's abortion ban. As far-right and conspiracy channels began referencing each other, YouTube's recommendation system linked their videos together, creating the impression of a unified truth. Diniz received threats of rape and torture, with some individuals even knowing her daily routines. Küster's videos were filled with repeated claims, according to Diniz. Despite not directly supporting them, Küster mentioned the threats with enthusiasm, staying just within YouTube's guidelines. When Diniz's university received a warning about a potential shooting and the police could no longer ensure her safety, she decided to leave Brazil. Diniz criticized the YouTube recommendation system for creating a hateful environment, where viewers are exposed to extremist ideas. She emphasized the need for companies to take responsibility for their role in spreading hate speech. From an ethical standpoint, they hold responsibility. As misinformation spreads on YouTube, content creators are targeting aid organizations involved in controversial issues like abortion. Even individuals who have historically supported these organizations are beginning to question the validity of the videos and are avoiding them. In Brazil, this online trend is referred to as "lynching." Bolsonaro was an early adopter of this tactic, spreading videos in 2012 that falsely accused leftist academics of planning to distribute "gay kits" in schools to convert children to homosexuality. Jordy, a protege of Bolsonaro from Niterói, was unfazed to learn that his own YouTube campaign, which accused teachers of promoting communism, had severely impacted their lives. One of the teachers, Valeria Borges, mentioned that she and her colleagues were inundated with hateful messages, creating a climate of fear. Jordy, instead of denying this, admitted that instilling fear was his intention. He stated that they are engaged in a "culture war," which he sees as his purpose in office. The epicenter of this YouTube-driven political movement may be the Movimento Brasil Livre headquarters in São Paulo, which was formed to advocate for the impeachment of President Dilma Rousseff in 2016. The group's members are typically young, middle-class, right-wing, and spend a lot of time online. Renan Santos, the group's national coordinator, pointed to a door labeled "the YouTube Division" and described it as the central hub of their activities. Inside, a group of young men were working on editing videos, including one that sought to defend fascism as a right-wing ideology. However, there are concerns among some members about the negative impact of social media on democracy. Pedro D'Eyrot, the group's co-founder, referred to social media as a "weapon" that could be used irresponsibly by some individuals associated with Bolsonaro. He also mentioned the concept of the "dictatorship of the like," where reality is shaped by what gets the most attention online. One particular YouTube video titled "1964" was gaining popularity, arguing that Brazil's military coup in that year was necessary to prevent communism. This video had a significant impact on individuals like Dominguez, a teenager who believed his teachers had misrepresented the history of military rule. On the other hand, Borges, a history teacher who was targeted on YouTube, was reminded of the harsh realities of military dictatorship, including curfews, disappeared activists, and police brutality. Despite the disturbing content on social media, individuals like Matheus Dominguez credited YouTube with pushing them towards far-right political views. YouTube's success has been based on engaging users, which has inadvertently benefited extremist groups. An investigation conducted in the company's second-largest market revealed significant repercussions.