On June 13, nearly 70,000 fans flocked to San Francisco Bay Area Stadium for the first of six FIFA World Cup matches to be played in the arena. The game began at noon. But security preparations started hours earlier, when the stadium’s network of cameras, sensors, and scanners came online.

Long before fans watched Qatar and Switzerland take the field that day, the stadium watched the fans: tracking faces at the gates, flagging suspicious sounds in the crowd, and feeding a constant stream of data to an on-site control center, where it then became accessible to a network of local, state, and federal law enforcement agencies coordinating security for the event.   

San Francisco Bay Area Stadium (usually known as Levi’s Stadium, though temporarily de-branded due to FIFA rules) is not an outlier. Across World Cup host cities in the United States, stadium security is linked to a broader federal surveillance apparatus overseen by the U.S. Department of Homeland Security (DHS). This system will not shut down when the World Cup ends: DHS budget documents reveal that the tournament is a testing ground for new surveillance technologies.   

DHS oversees events including the Super Bowl and World Cup because of a federal mechanism called the Special Event Assessment Rating, or SEAR, which designates events as national security priorities. That classification triggers coordination between federal and local law enforcement agencies.

DHS has classified World Cup matches as SEAR 1 and SEAR 2 events, meaning that they require the most stringent security; a SEAR 1 designation places the event in the same security planning tier as a presidential inauguration. These designations do not necessitate approval by event organizers, meaning that DHS coordinates with host cities and stadium operators, leaving FIFA with limited oversight in stadium security planning.

Hardware company Flock Safety helped to secure this year’s Super Bowl LX at Levi’s Stadium. According to an executive, Flock worked with the NFL, local law enforcement, and stadium security to deploy audio detectors throughout the venue, designed to alert law enforcement after identifying sounds like gunfire or general cries of “distress,” according to language from a since-deleted Flock advertisement. Flock remained embedded in World Cup security planning at Levi’s Stadium and venues across the United States, according to those with knowledge of the security plan and trackers such as open-source organization Deflock.

Another key vendor is IDEMIA, the same company that supplies the U.S. Transportation Security Administration with identity verification and biometric technology used at airport checkpoints. Pre-verified ticket holders and credentialed personnel enter stadiums through IDEMIA fingerprint or facial matching sensors.

Online surveillance technology—like cameras, audio detectors, or biometric scanners—at Levi’s Stadium is connected through the arena’s central nervous system of 400 miles of fiber-optic cable, which funnels collected information—things like video footage, sensor alerts, and access scans—to a locked data center operated by Cisco Systems. Fans can be tracked not just by face, but also by clothing: Flock’s platform deployed in some World Cup host cities allows security personnel to search footage using plain-language descriptions, such as “man in blue shirt and cowboy hat.”

Outside Levi’s Stadium, cameras with 20x zoom lenses monitor the surrounding streets at all times. “We don’t want to necessarily just capture a great crisp video of the attack, but when something bad does happen, we also want to be able to locate that person as soon as possible,” said Mike Sena, the executive director of the Northern California Regional Intelligence Center (NCRIC), a federally funded facility that coordinates intelligence sharing between local, state, and federal agencies across the San Francisco Bay Area.

NCRIC coordinates security at Levi’s Stadium alongside the Santa Clara Police Department and other state and federal law enforcement agencies, according to Sena. NCRIC uses Clearview AI, a facial recognition platform built from 30 billion images scraped from the internet without express consent, a Clearview executive told Foreign Policy in an interview. The executive, who spoke on the condition of anonymity to discuss sensitive matters, said the company’s database is meant for use only when authorities have identified an individual as a threat. Civil liberties groups dispute this claim; BuzzFeed News reported in 2021 that law enforcement had used the platform to identify Black Lives Matter protesters.

The European Union and Canada have effectively banned Clearview. But unlike many California jurisdictions, Santa Clara County does not prohibit its law enforcement from using facial recognition technology. In a statement to Foreign Policy, the Santa Clara Police Department said any use of surveillance technology is governed by “existing law.”

Under DHS’s definition, a stadium where the public has “unrestricted access” is considered a public place, meaning the surveillance network operating inside requires no warrant, regardless of whether fans understand the fine print when they buy a ticket.

“‘If you want to enter this arena, here’s a bunch of language that’s incomprehensible to a reasonable person.’ And so you click a box or do whatever, and they’re like, ‘Aha! You have consented,’” said Adam Schwartz, the privacy litigation director of the Electronic Frontier Foundation.

U.S. Immigration and Customs Enforcement (ICE)’s fiscal year 2026 congressional budget justification makes the connection between the World Cup and federal law enforcement explicit. It lists the World Cup and the America 250 celebration together as a $25 million line item under its Homeland Security Investigations (HSI) division. That budget puts HSI agents in the field, equipped with license plate readers, facial recognition platforms, and location data, obtained commercially or through legal processes.

Those are the same technologies that Flock and its partners supply to law enforcement nationwide. In February, the then-acting ICE Director Todd Lyons maintained that the agency would play a “key part” in security operations at the World Cup. FIFA management has reason to be worried about the presence of ICE agents at the tournament: Since the start of this year, federal immigration officers have shot and killed four people, and 22 individuals have died in ICE custody.

Last year’s FIFA Club World Cup, played across the United States, offered a preview of what ICE’s presence at the tournament might look like. During the Club World Cup final at New York New Jersey Stadium (usually known as MetLife Stadium)—the same venue hosting the final on Sunday, July 19—a father was detained in the parking lot after his small drone, which he was using to take a photo of his family, malfunctioned. He was handed to ICE by local police, held for three months, and deported, despite his claims that his life was at risk in his country of origin.

The man was never charged with a crime. His last memory of the day, he told Human Rights Watch, was “seeing my kids cry because I was captured.”

Yet FIFA President Gianni Infantino showed no sign of concern about the U.S. security apparatus bearing down on fans as he cozied up to U.S. President Donald Trump. However, internal discussions at FIFA reported by The Athletic show that management at the organization was concerned about U.S. security forces under the Trump administration and pushed Infantino to ask Trump for a moratorium on ICE raids during the summer.

Although enforcement action has been quiet within stadium grounds, ICE has been active in host cities during the tournament. In Kansas City, ICE arrested at least 30 residents during the period that the city hosted matches, according to local advocacy groups, who say the pattern is consistent across many U.S. host cities. ICE arrests have surged around the country in recent months at the direction of the White House.

The World Cup comes as DHS is developing more advanced technology to use in the field. Last September, DHS awarded a $4.6 million contract to BI2 Technologies, a Massachusetts company whose core product, the Mobile Offender Recognition and Information System, was designed to identify subjects against a criminal booking database. In May, DHS expanded its contract with BI2 to $25 million.

The contract, active through the entire World Cup, makes the technology available to HSI agents operating in and around tournament venues, giving agents access to iris recognition hardware and a national database of 5.1 million criminal booking records drawn from corrections facilities across the country. According to the contract, its stated purpose is to allow ICE agents to “quickly authenticate the identity of subjects during field operations.” (BI2 did not respond to Foreign Policy’s multiple requests for comment about its use in the field or at the World Cup.)

DHS did not respond to multiple inquiries about the World Cup surveillance apparatus, including whether technology deployed at stadiums would be removed after the final match. But in April, DHS released its Science and Technology budget justification for fiscal year 2027. The document explicitly states that the department plans to use the World Cup to “deliver a final assessment of the performance of a 360-degree camera and a video analytics capability” for a “large scale public event.” The same budget names the 2028 Olympics in Los Angeles as the next test case.

History suggests that surveillance infrastructure built for one purpose rarely remains limited to it. Miami police, for example, acknowledge using Clearview AI to investigate crimes from murder to shoplifting—the latter of which is a far cry from the violent crime investigations that the technology was marketed toward. In an acknowledgment of this reality, Seattle Mayor Katie Wilson deactivated stadium surveillance cameras in the city after it hosted its last World Cup game earlier this month, citing concerns about federal overreach and civil rights.

“The system goes up to find mass murderers,” Schwartz said. “And before you know it, the system is finding people who didn’t pay a parking ticket and people who are immigrants, people who are seeking an abortion, protesters.”

On Sunday at New York New Jersey Stadium, a whistle will blow and either Argentina or Spain will win the World Cup. Millions of people will rejoice, and millions more will be disappointed in their country’s team. Some 82,000 fans will leave the stadium and head for their cars, a bus, or the train station.

Weeks later, once all the fans have returned to their homes, the cameras will still be on at MetLife Stadium, Levi’s Stadium, and all the other U.S. tournament venues, sending information to data centers and around the country. The World Cup will be finished, and DHS will have its trophy: layers of data collected and surveillance infrastructure tested, all ready for the next event.