The Professor Who Built an App to Track ICE—And Became Its Target
It had been less than a week into the second Trump administration when Rafael Concepcion stumbled on a Facebook post that would completely upend his life. The post was written by Maria Hernandez, owner of a Mexican grocery store beloved by Latino residents in New York’s Finger Lakes region. She shared that several of her most loyal regulars had already gone into hiding. With sales crashing, she announced she would deliver free groceries to anyone too frightened of U.S. Immigration and Customs Enforcement (ICE) to step outside their home.
Concepcion, a second-generation immigrant and professor at nearby Syracuse University, was so moved by Hernandez’s act of generosity that he made the 45-minute drive to her shop to pay his respects and spend money locally. At 51, he’s a large, outgoing man with slicked-back hair; on that visit, he wore a black V-neck tee and blue jeans as he browsed aisles stacked with pan dulce, fresh tomatillos, and religious prayer candles. Stopping in front of a refrigerated display case, he noticed an African American customer studying packages of chorizo. The man assumed Concepcion worked at the store, and told him: “I don’t know what any of this is, but I saw the post on Facebook and wanted to come in to show my support.”
That trip to Hernandez’s store stirred something deep in Concepcion: a long-simmering moral discomfort that slowly grew into an all-consuming mission to block ICE’s work. In early February 2025, he wrote about his experience at the Mexican market—located not far from Harriet Tubman’s former home—in an op-ed for the Syracuse Post-Standard. “I plan to help in any way I can. I hope you will too,” he wrote. “History should be able to count on us to do the right thing.”
When the column drew dozens of angry responses (“How about FOLLOWING THE LAW. You people make me sick”), Concepcion knew polite opinion pieces weren’t enough. Since Trump’s latest inauguration, ICE had already tripled its daily arrests to more than 600, and gentle calls for action would not move the needle. He needed to escalate his activism.
Before joining the faculty of Syracuse’s prestigious Newhouse School of Public Communications to teach multimedia storytelling, Concepcion spent two decades working on the periphery of the tech industry. So he decided to build a mobile app that would teach immigrants how to exercise their constitutional rights when stopped by ICE agents.
Concepcion, who describes himself as having “the worst case of ADD you’ve ever seen,” became completely hyperfixated on the project. (The black V-neck and jeans he wore to Hernandez’s store are his everyday uniform: he owns 30 identical shirts and 30 identical pairs of pants to avoid decision fatigue.) He relied heavily on AI tools like Cursor and ElevenLabs to build the app, fueled by massive amounts of caffeine. “I drink, like, 14 cups of coffee a day,” he told me. Most of his “vibe coding” happened between midnight and dawn, as he sat parked outside a local Home Depot in his electric F-150 pickup. He chose the spot to feel closer to the day laborers he hoped the app would serve, and worked to a loop of the entire Hamilton cast recording.
By April, as ICE ramped up enforcement raids from Maine to California, Concepcion got a panicked message from a chef at one of his favorite local Latin restaurants. The chef’s adult son—who I will refer to only as Gabriel to protect his privacy—was driving to a construction job in nearby Oswego when Border Patrol agents pulled him over. A native of Mexico, Gabriel showed agents his immigration paperwork confirming his asylum case was still pending, but they refused to halt the process. He was taken to an overcrowded ICE detention center in Batavia, New York, located between Buffalo and Rochester. The distraught chef, who everyone at the restaurant called “El Profe” (the Professor) when referring to Concepcion, asked for his help getting Gabriel released.
Concepcion has always loved stepping in to help people failed by the immigration system, so he threw himself into securing Gabriel’s freedom. He found a lawyer willing to take the case for $4,000, then wrote a character reference letter to the judge on Syracuse University letterhead. After several stressful weeks, Gabriel was released on $10,000 bail—a rare outcome in 2025, when release rates dropped 87 percent year over year. Concepcion volunteered to make the two-hour drive to pick him up from detention.
The ride home was unsettlingly quiet. As Concepcion watched the exhausted, defeated young man beside him, he began to regret the mild, educational focus of the app he was building. What good was teaching immigrants their rights if federal agents just ignored those rules to hit their arrest quotas? Concepcion realized he needed to build a tool that could “stop these people from falling off a cliff, stop these people from disappearing.”
He overhauled the app to give it a far more aggressive purpose. The new version let any user report ICE activity by dropping a pin on a shared map. Users within a close distance of the pin would get a push notification with detailed information, including photos, of agents’ locations and vehicles. The intel could be used to organize spontaneous flash protests or help people find safe shelter. He named the app DEICER.
When it came time to submit DEICER to Apple’s App Store, Concepcion’s anxiety spiked. He worried the federal government would pressure Apple to hand over a list of all accounts that had downloaded the app. But he decided to move forward anyway. “ICE is looking for millions of people,” Concepcion said in a video marking DEICER’s official launch on July 28. “What if millions of people were looking for ICE?”
With that launch, DEICER joined a small but growing group of crowdsourced mapping tools—including ICEBlock and the Stop ICE text alert network—created in response to the Trump administration’s mass deportation campaign. These tools were designed to level the playing field against ICE, which has far more advanced technology than the loose coalition of activists opposing it. With an annual budget of more than $77 billion, ICE has built out a suite of Palantir-powered tools that can pinpoint immigrants for arrest. The resistance, by contrast, has had to rely on the ingenuity of independent operators like Concepcion, whose obsessive drive has already put him in conflict with internet trolls, hackers, right-wing media conglomerates, and the world’s second-wealthiest company: Apple.
A Life Shaped by Immigrant Community
Concepcion grew up in the South Bronx in the late 1970s and early 1980s, a time when the neighborhood was synonymous with urban decay. His Puerto Rican father worked as a janitor and often scavenged for scrap copper to earn extra money to buy fresh loaves of bread for his seven children. His mother was an immigrant from Puebla, Mexico, and a rotating group of her acquaintances—people she called “uncles” and “cousins”—stayed at their apartment while they looked for under-the-table work. Concepcion still remembers being struck by how men who had worked as engineers in Mexico were grateful to take jobs as dishwashers in the U.S.
A talented student, Concepcion escaped the Bronx to attend a state university in Plattsburgh, a remote town on the icy shores of Lake Champlain. He originally planned to become an English teacher, but his path shifted when he discovered the internet. He spent much of his college career experimenting with the text-based web browser Lynx and the VAX operating system. After graduation, that experience led him to a job taking customer support calls for IBM, then a role leading software training for a German e-commerce company, and eventually a long career writing a popular series of guides to Adobe Photoshop.
In 2018, Concepcion settled in Syracuse with his wife, an elementary school teacher, and their young daughter to take a curriculum development job at the university. He also taught a storytelling class as an adjunct, which led to a contract as an assistant teaching professor in 2022. It was his dream job: a chance to serve as a role model for two groups of students in particular—those who share his Latino roots, and those navigating mental health challenges. “I’m very open with my students,” he says. “I struggle with ADD, I struggle with depression, I’ve had mental health crises.”
Concepcion also grew to love Syracuse, a Rust Belt city of 146,000 known for its heavy annual snowfall and high childhood poverty rate. He was inspired to see some of the city’s most run-down neighborhoods revitalized by new arrivals from Syria, Burma, and South Sudan. (Between 2000 and 2014, Syracuse’s foreign-born population grew by more than 42 percent.) To bring that diversity to campus, he served multiple terms as chair of the Newhouse School’s DEI committee. In 2023, he and his wife became foster parents, taking in a 14-year-old girl who had been living in a drug-ridden home on Syracuse’s South Side. One of 13 siblings, she had used a closet as her bedroom; Concepcion’s wife, a former ballerina, first met her while teaching a local dance class.
As Concepcion put the final touches on DEICER in early summer 2025, he got bad news from the university. Three weeks before the end of the semester, he says a dean told him a full professorship they had discussed was no longer available, though he was welcome to apply for an administrative back-office role. The cut came as the university scrambled to comply with the U.S. Department of Education’s order that elite colleges eliminate all DEI programs and initiatives.
After DEICER was downloaded more than 3,000 times in the days after its App Store launch, Concepcion got a flood of emailed death threats—so many that he started shopping for a bulletproof vest. Syracuse’s student newspaper published an op-ed calling DEICER a “revolutionary tool for immigrant communities” and shared Concepcion’s fear that he was being pushed out of the university because of his political activism. Soon after, Concepcion was told he was no longer being considered for the back-office role. (A Syracuse spokesperson told me the university is “unable to comment on personnel matters” but that they “appreciate Rafael’s contributions to the Newhouse School and wish him the best in his future endeavors.”) For the first time in years, Concepcion was unemployed. I first connected with him shortly after this setback, and we soon began talking in a series of long phone calls.
Clash With Apple
On October 2, roughly two months after DEICER launched, the U.S. Department of Justice contacted Apple to demand the removal of all apps that “put ICE agents at risk for doing their jobs.” The next day, Concepcion got an email from Apple explaining that DEICER, which by then had roughly 30,000 users, had been removed from the App Store. The company said the app’s “purpose is to provide location information about law enforcement officers that can be used to harm such officers individually or as a group.”
In effect, Apple classified ICE agents as a protected class on par with racial and ethnic minorities, meaning DEICER violated the App Store’s ban on “defamatory, discriminatory, or mean-spirited content” that targets protected groups. ICEBlock, which Attorney General Pam Bondi had named as a target for criminal investigation, was removed from the store the same day for the same reason.
Apple’s surrender to the Justice Department showed how much the company’s priorities have shifted over the past decade. In 2015 and 2016, Apple fought a fierce legal battle when the government, panicking over ISIS-inspired terrorism, tried to force the company to build security “backdoors” into iPhones. Today, the company seems to prioritize friendly relations with the Trump administration above all else—a necessary calculation, likely, to avoid crippling tariffs and other political retaliation. (Apple did not respond to a request for comment for this story.)
Concepcion proved far less willing to back down than the tech giant. To appeal the removal, he submitted a modified version of DEICER to the App Store that he thought would address Apple’s concerns. In the updated app, pins no longer included specific information about ICE agents; instead, they simply notified people that they could gather at the marked location to “exercise your First Amendment right to constitutional assembly.” The change did nothing to convince Apple, which rejected the appeal on the exact same grounds as the original removal.
As he weighed DEICER’s next move, Concepcion kept the core product available as a web-only app and launched a handful of related projects. He quickly built hyperlocal versions of DEICER whenever federal agents raided a new city: he made a custom web app for Chicago after ICE launched Operation Midway Blitz, then another for Portland, Oregon after Trump sent hundreds of National Guard troops to both cities. “It almost feels like I’m just trying to dress DEICER up in a chicken suit to try to get people to use it,” he told me. “But I don’t really care as long as they use it.”
The “chicken suit” workarounds rarely gained traction, largely because they lacked local community networks to direct users to them. That changed when Siembra NC, a North Carolina-based immigrant rights group that had reached out to Concepcion soon after DEICER’s launch, hired him to build a custom version of the tool for their state.
Siembra had been studying ICE-monitoring tools since spring 2025, and the group had concerns about the unvetted nature of most existing platforms. “Most of them are just rumor mills,” says Andrew Willis Garcés, Siembra’s senior strategist. “They give people the sense that they’re doing something, and it’s a way to channel anxiety, but they don’t actually help them get better at identifying the patterns, the tactics the administration’s using. And so they contribute to a generalized anxiety that I think is part of Stephen Miller’s goal. He would love it if there was maybe a thousand of these, and you couldn’t tell what was real.”
Siembra liked DEICER’s design, and hired Concepcion to build a North Carolina-specific version called OJO Obrero (“Look out, workers”), which added a layer of moderation for user-submitted tips. The plan called for Siembra volunteers to verify reports before pins went live on the map. This meant users wouldn’t get real-time updates on ICE agents’ movements, eliminating one of the core features that inspired Concepcion to build DEICER. But Siembra argued a cautious approach was necessary to build reliable intelligence about ICE’s patterns—for example, what times of day agents most often patrol certain highways, and what types of vehicles they target.
OJO Obrero was still in beta testing on November 15 when Concepcion drove his foster daughter to her school’s winter choral recital. As he waited in the auditorium before the performance started, he scrolled Instagram and froze when he saw a Reel from Siembra’s account. Hours earlier, hundreds of federal agents had launched a massive raid across North Carolina, the first operation in a Department of Homeland Security campaign codenamed Charlotte’s Web. Siembra’s representative emphasized the group was ready for the crackdown: “Siembra NC created a resource called OJO Obrero,” she said, “a website you can go to to track confirmed sightings of ICE agents by location and by time across the state.”
OJO Obrero was pushed live abruptly, even though in Concepcion’s view it was nowhere near ready to handle a massive flood of traffic. During testing, he had averaged around 3,000 database requests per day to the platform that hosted OJO Obrero’s mapping features. As Charlotte’s Web became national news that day, requests spiked to an unmanageable 75 million, crashing the site and leaving Concepcion with an $8,000 usage bill he had to pay out of pocket.
But Concepcion quickly fixed the technical glitches and stabilized the site. Siembra assigned 30 of its most tech-literate volunteers to vet the flood of incoming tips. Within days, the group was able to share key patterns with users, such as agents’ habit of pulling over white work vans. “You could see day-to-day, OK, this is kind of the pattern that they were doing yesterday, so probably today might look similar,” says Garcés. “And so it really helped people think about how to stay safe.”
But Concepcion took little joy in OJO Obrero’s success. He was increasingly disturbed by his social media feeds, which were flooded with videos of crying people being dragged into unmarked SUVs. Like millions of others, he found himself trapped in what he calls “the algorithmic rage loop.” And he began to question whether work like his could avoid feeding this harmful cycle.
On the Ground in Syracuse
After two months of talking on the phone with Concepcion, I drove up to Syracuse in December, arriving just as a dangerous overnight snowstorm began to cover the city. The next morning, Concepcion took me to meet Gabriel and his father at the Latin restaurant where they both work. Gabriel, who has a young, round face, came out of the kitchen to show us his ankle monitor, which he said was so scratchy it was almost unbearable. His cheerful father insisted on serving me a huge plate of barbacoa. As he scooped it out of steam trays under a sign that read “Welcome to Our Home,” he told me in Spanish that just the day before, masked men had arrested someone at the gas station across the street.
As Concepcion and I ate in the fluorescent-lit dining room, six men in high-visibility work vests came in for lunch. Concepcion introduced himself and learned they were undocumented Brazilian workers doing road repair across the Northeast. He then showed them how to add a shortcut for the DEICER web app to their phones’ home screens. The men were polite but skeptical that the app would do much to help them.
Concepcion is used to this skepticism. In the months since his fight with Apple began, he has come to believe tools like DEICER are failing to reach their target audience. Instead, he worries they are mostly used by well-meaning activists who want to film ICE raids and share the content with communities that already oppose the Trump administration’s immigration policies. Concepcion argues this content exhausts viewers, pushing many to step back from a fight that algorithms frame as unwinnable. And immigrants keep getting arrested and deported, no matter how many cameras capture their suffering.
Concepcion’s solution is for community groups that have spent years building trust with immigrant communities—like Siembra—to spread the word about tools like DEICER. He insists crowdsourced monitoring tools can give immigrants a 20-minute head start when ICE is on the way. (Concepcion sees no legal issue with these alerts, comparing them to the police activity warnings Google Maps already provides.)
But many local immigrant groups have
