For decades, Republicans and Democrats agreed that a “smart wall” of surveillance cameras and other high-tech equipment would be a potent tool to stop illegal immigration and drug trafficking across the southern border. Now, the smart wall has arrived — and it is more powerful than many could have imagined.

Already, more than one million people in the United States and Mexico live in areas along the border where they can be seen by A.I.-powered surveillance towers, a New York Times analysis found. At least four million more live within view of an older generation of cameras that the government plans to retrofit with A.I. technology.

And the Trump administration has secured more than $1 billion to build 1,500 new A.I. towers. The goal is full coverage along the U.S. border with Mexico, and there are plans to install towers near Canada, as well as in coastal areas and in Puerto Rico.

But a rising public backlash against A.I. and growing anxiety over mass surveillance have left some communities with an uncomfortable question: Is the potential loss of privacy worth it?

To understand the new technology, Times reporters visited two dozen A.I. towers in California, Arizona, New Mexico and Texas and used a drone equipped with a camera to recreate what the towers can see.

In Sunland Park, N.M., near El Paso, a tower sits on a hill, scanning the border wall. It can also watch large sections of the city.

The tower’s camera can capture a detailed image up to roughly two miles away. After its radar detects significant movement, the camera pans and zooms to the target.

Then an A.I. model classifies the image as a human, animal or vehicle and alerts Border Patrol agents in a command center. Those agents can view the footage and decide how to respond.

This footage shows The Times’s approximation of what the Sunland Park camera can see in three locations around the city — and how its A.I. tools work.

The tower cannot see everything. There are some gaps in its vision because of the terrain and buildings.

To more accurately assess the area visible from the tower, The Times analyzed its height, radar range, camera resolution and the surrounding landscape.

The towers make up one of the largest visual surveillance programs operated by the federal government. They can see much farther than the Flock license plate readers that have been criticized as privacy invasions.

And the A.I. technology means the towers can watch their surroundings 24 hours per day, operating with far greater efficiency than cameras monitored by humans, who tire and get distracted.

Hilton Beckham, an assistant commissioner of public affairs at Customs and Border Protection, said in a statement that the new towers were “essential to border security.”“Any capability that improves an agent’s awareness and ability to assess potential risks helps protect agents, migrants and the public,” she said.

She added that the agency “employs technology while respecting civil liberties and privacy interests.”C.B.P has the ability to black out certain areas on camera feeds, shielding them from view, according to people with direct knowledge of the program who spoke on the condition of anonymity to discuss law enforcement matters. But it can remove those restrictions at any time. The agency did not answer questions about where or how often it uses this feature.

In privacy guidelines, C.B.P. says that it can share surveillance footage with local, state and federal law enforcement authorities — and even foreign governments. The agency also acknowledges that people near the border cannot “opt out” of being surveilled, noting the risk that those who are “engaged in First Amendment protected activities” or are “complying with the law” could be recorded.

Officials did not provide information that would demonstrate how well the towers worked, such as how many times they had helped catch migrants or drug smugglers.

The towers are just one part of a vast surveillance system at the southern border. C.B.P. also employs drones, license plate readers, trail cameras, ground sensors and even blimps. Officials are working to build a single technology platform where agents can see data from all of those sources.

Opinions in border communities about the new towers vary. Some residents welcome them after millions of migrants crossed during the Biden administration. Others see them as potentially violating their civil liberties.

“We don’t want to be surveilled by our government,” said Gene Belmares, a Republican former city councilman from Laredo, Texas, who urged members of his party to imagine the towers under the control of Democrats.

But few border residents interviewed by The Times knew what the towers did or how powerful they were. Most thought they were cell towers or radar equipment.

A ‘smarter’ wall As part of the long-running push for a virtual smart wall, C.B.P. installed hundreds of towers with standard surveillance technology over the past two decades.

Some of these efforts were expensive failures, in part because agents were expected to monitor too many cameras at once. A.I. towers were designed as a solution. The government began testing them in 2018.

C.B.P. now operates at least 350 A.I. towers, both in remote and populated areas. The Times was able to locate 209 of these towers, and found that at least 180,000 U.S. residents and 850,000 people in Mexico live within their view.

They stretch from California, where there is one at the end of the Pacific Crest Trail, to the Texas gulf coast, where another watches Starbase, Elon Musk’s company town. They sit on federal land or plots leased from local governments and private owners.

Current and former C.B.P. officials described the new towers as a major upgrade over the previous generations.

Rush Carter, a former Border Patrol official, said agents apprehended many more migrants after an A.I. tower was installed in the flat, open land near Valentine, Texas.

“If you put them in the right place and you have personnel,” Mr. Carter said, migrants will “quit using the area.”The Government Accountability Office, an independent federal agency, has found problems with the program.

One audit this year concluded that C.B.P. had not established a basic master plan outlining the program’s cost, timeline for delivering towers or metrics for measuring success. Another in 2024 determined that the agency’s internal technology policies did not address how the towers would store and secure sensitive personal data.

The towers have also proven less effective at spotting illegal activity in congested urban areas with more people, vehicles and construction activity, according to six current and former government officials with knowledge of the program.

Dave Maass, the investigations director of the Electronic Frontier Foundation, a civil liberties group tracking the towers, called the program a “costly boondoggle.”

“Every few years, they make these amazing claims about the technology,” Mr. Maass said. “And then an oversight body looks at it and finds it’s a big, wasteful program that is not delivering results.”Always watching The contractor building most of the towers is Anduril, an A.I. defense firm that has close ties to Mr. Trump.

Anduril won contracts during Mr. Trump’s first term and also under President Joseph R. Biden Jr. Like many Democrats, Mr. Biden said he preferred a smart wall to a physical barrier. Since Mr. Trump’s re-election, the firm has secured more than $567 million in new contracts from C.B.P.

The agency recently approved three other companies to build A.I. towers, which range in height from roughly 18 to 120 feet. Some can see as far as 10 miles.

All include the same core technology: a panoramic radar system, powerful day and night cameras, an onboard A.I. computing unit and data communication antennas. They are not equipped with facial recognition software, the agency says.

Radar Visible light camera Weather sensor Onboard computer and communications Infrared camera Radar detects movement Cameras swivel and capture target A.I. interprets sensor data and alerts Border Patrol Data from the towers is maintained on government servers. With authorization from C.B.P., it can be accessed by contractors like Anduril to improve their models or to monitor equipment.

The agency generally keeps the data for 30 days, unless it is needed for law enforcement purposes, according to government records. But officials have also said that data used for training A.I. systems “should not be deleted.”Shannon Prior, a spokeswoman for Anduril, said its towers had proven “highly effective” at securing the border. She also disputed The Times’s analysis of how many people they could see.

“Our technology can be programmed by customers to prevent monitoring of designated areas,” Ms. Prior said in a statement. “Your analysis does not appear to account for this context, therefore conclusions about what is actually being monitored may be misleading.”‘It follows you’Eloisa Cavazos has lived in a house near the Rio Grande, which separates Texas from Mexico, since the mid-1950s. Now, there is an A.I. surveillance tower across the street.

Ms. Cavazos, 75, said she understood the need to watch the border and liked the tower more than the wall behind it. Still, she wished it had been placed somewhere more remote.

“It can see when I leave, who I’m with, who’s coming and going from our house,” Ms. Cavazos said. “It follows you.”Eric Chapa, who lives in Laredo, said that during the Biden administration, migrants and drug traffickers regularly crossed the river at the athletic fields where he coaches a youth soccer team.

“It felt risky to come down here,” Mr. Chapa, 40, said, adding that border crossings had slowed under Mr. Trump and that he hoped a nearby A.I. tower would keep it that way. “I hope it makes people think twice.”To others, the towers have simply become a fact of life.

“We do our everyday routine and forget,” Antonio Nuñez, 56, said as he cleared leaves from outside his home in Sunland Park. “We get used to it.”As the program expands, the towers will move into areas beyond those that Americans traditionally think of as the border.

More are likely to pop up in places like the popular beach in Del Mar, Calif., about 30 miles north of Mexico, where C.B.P. installed an A.I. tower in 2021 to detect boats carrying migrants and drugs.

This year, C.B.P. secured a lease from the beachside city of San Clemente, Calif., about 70 miles from Mexico, to install a tower on a hill overlooking the community. San Clemente, Calif. City officials said the tower would prevent deaths after several episodes in which migrants drowned. But some residents and elected officials pushed back. The agency says plans to install the tower are on hold, for now.

Steve Knoblock, a San Clemente councilman who supports the tower, said border security outweighed any privacy concerns.

“This is the world we live in,” Mr. Knoblock said. “There are cameras everywhere. You walk down the street here, you’re being recorded. You can’t put the genie back in the bottle.”About this story Customs and Border Protection does not publish information on tower locations or type, and the agency did not provide the number of towers in operation. The Times assessed the scale of the border tower surveillance program through a combination of aerial and satellite imagery, geospatial analysis and extensive field reporting.

We started with data on tower location and type from the Electronic Frontier Foundation and validated the data, establishing a timeline of tower construction. With additional field reporting, we located and analyzed a total of 567 towers out of the roughly 830 in operation. As a result, our findings most likely understate the number of people living within the view of all existing towers.

For that analysis, we computed the area visible from each tower using local and state surveys and United States Geological Survey terrain data, and used population data from the 2020 censuses in the United States and Mexico.