In São Paulo, ‘Big Brother’ is watching, with 25,000 cameras and facial recognition technology

In São Paulo, Brazil, the fugitive probably felt protected by the anonymity offered by a city of 12 million people… a larger population than many countries. Germano Euclides Paciência, 48, looked like just another nondescript guy. He wore a red T-shirt, blue shorts and a white cap. But behind that facade lurked a rapist who had been on the run since 2018, after being sentenced to eight years in prison.

Paciência was identified on Friday, February 7, 2025. He was crossing an overpass toward a municipal health center, when a camera scanned the faces of passersby. By using an artificial intelligence engine, the camera instantly compared those images with a database of fugitives. Bingo! The alert went off in a building in downtown São Paulo, at the heart of the vast video surveillance system that has turned the most populous city in the southern hemisphere into a colossal “Big Brother.”

The gigantic network — with some 25,000 cameras (some of them hidden) recording day and night — is dubbed Smart Sampa. Six months after its implementation, Mayor Ricardo Nunes is enthusiastic about the results. As of Friday, April 25, 1,044 fugitives have been arrested — including murderers, rapists, cell phone thieves, a member of the Chinese mafia, etc. — while 2,289 criminals have been caught red-handed. Additionally, 60 missing persons have been located. And all of this took place, Nunes emphasized in a recent interview, “without firing a single shot” and “without a single mistake.”

Smart Sampa is the darling of his second term. An ally of former president Jair Bolsonaro, Nunes’ principal objective is to combat crime and manage public safety, which is the main concern of the people of São Paulo.

The arrest of Paciência illustrates how the system works. Once the alert is triggered at the headquarters, the police confirm that the arrest warrant is valid and radio the patrol cars closest to the suspect. In this case, three officers from the Municipal Guard showed up at the clinic 16 minutes after the fugitive arrived. The officers — one of them with his weapon drawn, but almost hidden from view — crossed a waiting room under the gaze of several women with babies on their laps, according to images recorded inside the health center. In less than a minute, they emerged with the suspect detained, surrounded but not handcuffed.

The system is managed by a consortium of Brazilian companies. These firms utilize an artificial intelligence-powered software called FindFace, from the Russian-based company Ntechlab. Each arrest is recorded on the “prisonometer,” an electronic panel placed in front of Smart Sampa’s headquarters in the historic center of São Paulo.

In the Smart Sampa operations room, the mayor explains that he was inspired by the experiences of cities like London, Buenos Aires, and Miami, which drastically reduced crime with a trio of measures: more officers, larger security budgets, and improved technology. He says that, having already adopted the first two, he tackled the third: “When I have the Red Command, Amigos de Amigos (ADA), the PCC here…” he sighs, listing powerful organized crime groups, “as well as a situation in which a huge number of fugitives are roaming the city with impunity, it’s impossible for the police to be arresting everyone. The only way to remove them from circulation to protect society — and place them where [the justice system] has decided they should be — is through technology.”

After initial reluctance, the mayor’s team emphasizes that, to avoid errors, they’ve adopted a strict protocol whereby the alarm is only triggered when the match (between the features of the passerby and the fugitive) exceeds 92%.

Little by little, facial recognition has crept into the lives of millions of Brazilians. First, it appeared at the entrances to high-rise buildings in large cities, in the name of innovation and cost savings. Overnight, it replaced traditional doormen. Then, it appeared at the bank. And, in no time, posing for a camera and leaving your ID at the front desk became a routine procedure for entering many buildings.

In São Paulo, the City Council already monitors health centers, community centers and the outdoor areas of schools. And it has begun installing cameras on city buses. “This way, if a passenger bothers a woman, we’ll stop him,” the mayor notes. Private companies are increasingly joining the deployment, feeding their cameras into the municipal system. Mayor Nunes exultantly reports that the Supermarket Association, with 7,300 units in the city, has just offered to collaborate. And, in his office, he regularly receives mayors who want to get a glimpse of the ins and outs of this so-called “Big Brother.”

More than a third of Brazil’s 212 million people are potentially being monitored with facial recognition systems in the name of public safety. This is being done through 376 projects implemented by cities across Brazil, according to the Center for Studies on Public Security and Citizenship (CESeC). Yet, even in this context, Smart Sampa represents a milestone due to the sheer scale of the network.

For CESeC researcher Pablo Nunes, “the idea of the prisonometer and this spectacularization of surveillance via facial recognition technology is very new. It raises the question of whether this will be a turning point in the narrative of future projects.”

Football stadiums and large carnival gatherings have been testing grounds for a technology that has had some notable failures. Pablo Nunes (no relation to the mayor) is concerned about the errors that facial recognition makes with Black people and other underrepresented groups when sifting through the raw material used to train the algorithms. He mentions a study conducted in the U.S. that revealed how facial recognition error rates are less than 1% for white men, but 34% for Black women. The researcher emphasizes that less than 1% of the vast population being monitored represents many thousands of people who are mistakenly identified.

Mayor Nunes responds disdainfully to any mention of the misgivings expressed by civil society organizations: “These entities have no legitimacy: 98% of the 12 million residents [of São Paulo] approve of Smart Sampa. That carries much more weight than any organization that brings together half-a-dozen people to criticize [this network].” He adds that the system is overseen by the Public Prosecutor’s Office and that there’s a governing council.

Images recorded by Smart Sampa cameras are kept for 30 days. The system also serves to locate missing persons and stolen vehicles, as well as vehicles whose owners are wanted. It can assist abused women who have sought restraining orders, or mobilize firefighters when a tropical storm knocks down trees. It costs about 10 million reais a month — around $1.7 million — to maintain.

São Paulo is far from having the worst rates of violence in Brazil, because there’s no conflict between criminal gangs: the metropolis’ territory is dominated by the PCC (Primeiro Comando da Capital). But the daily theft of cell phones and several high-profile assaults in quiet neighborhoods — some of which ended in murders — have fueled fear. This is one of the reasons why privacy is of secondary importance to most people.

But Rafael Zanatta, co-director of the NGO Data Privacy Brasil, sees several risks that may not be immediately apparent. He explains that Brazil offers excellent raw material for training artificial intelligence, because it has a huge population with a level of ethnic diversity difficult to find anywhere else. Brazilians can look German, Nigerian, Korean, Moroccan, or Portuguese. “And, in a metropolis like São Paulo, the number of behaviors that occur in public spaces is enormous: a vendor [selling hot dogs], a mother who has lost her child, a sexual harasser hunting for women, an exhibitionist, someone selling drugs on a street corner, or [a person] waiting for someone. There are many human behaviors available to be cataloged. And that’s the business: predictive technology.”

“These companies are looking at the 2035 market,” he adds, referring to companies like Edge Group from the United Arab Emirates, which just signed a contract with the São Paulo state government to conduct video surveillance. For now, the state and municipal systems operate independently, but Data Privacy Brasil warns that a hypothetical integration could open the doors to private companies profiting from the valuable raw material obtained for the purpose of public safety.

The municipal mantra is that “those who haven’t committed a crime shouldn’t worry.” For São Paulo’s security councilor, Orlando Morando, “people have already learned to live” with video surveillance. “[Only criminals and thieves] are afraid,” he states emphatically. “I’m convinced that good citizens are happy to be recorded and monitored.”

Morando proposes a new version of the slogan that accompanies so many cameras in elevators and shopping malls: “Smile, you are being protected.” The mayor of São Paulo, meanwhile, dreams of quadrupling the number of cameras to 100,000 by the end of his term in 2028.

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