One Nation, TRACKED

On Nov. 19, 2016, kids in tow, Margie Homer drove from her home. She pulled into the lot of the Pasadena Waldorf School in Altadena, Calif., at 10:26 a.m. It was a gorgeous, clear morning, and she and hundreds of others walked among the bales of hay and suits of armor decorating the grounds for the annual holiday Elves’ Faire. At 12:49 p.m. she pulled out of the lot, heading back down East Mariposa Street the way she came.

All afternoon the city hummed in every direction. Across town, K. was en route to a lunch at Din Tai Fung, a Taiwanese restaurant in Arcadia where he’d arrive at 1:34 p.m. for a 54-minute lunch. M. stopped at Pasadena City College briefly, then made a trip to Home Depot. Others, like C. and J., went to church. There were evening errands: After a day with family, A. popped into a CVS at 6:57 p.m. C. took an evening trip to Costco. T. made a stop at AutoZone in Rosemead. Hundreds more shopped, ate, walked in the park, visited doctors’ offices and coffee shops, and a few checked into hotels at odd hours.

The only thing out of the ordinary for the good people of Pasadena, Calif., about this particular Saturday is that three years later and 3,000 miles away in a newsroom, Times Opinion watched their every move unfold all over again. Minute by minute and inch by inch.

We pieced together some stories from Pasadena over a period of several months. Our eye in the sky wasn’t a network of traffic cams or satellites but data exhaust spewing from smartphone apps buried in the pockets and purses of unsuspecting Americans.

Connecting location pings across Pasadena, Calif., revealed skeins of activity.

The Times Privacy Project was given access to a data set with more than 50 billion location “pings” from the phones of more than 12 million Americans across several major cities. Each piece of information came down to a set of coordinates in time. The result is a tapestry of movement laid across a city grid — like the computer game SimCity, only real.

This granular location data — the kind that is collected by hundreds of mobile apps and then shared with dozens of location data brokers — may seem like a catalog of the mundane. But the aggregate is closer to total surveillance — an exact record of the rhythms of a living, breathing community.

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Modern data surveillance relies on the ease of gathering but also the capacity to analyze giant sets of numbers. Run a set of numbers through a computer and the data becomes far more personal and invasive. Data points become a diary. A cluster of pings inside a secure facility reveals clues to the secretive role of an aerospace engineer. Visits to places of worship, trips to Planned Parenthood, a late-night visit to a bail bondsman — all collected in perpetuity and logged forever to be analyzed, traded and monetized. Each mark of latitude and longitude tells the story of the triumphs and tribulations of a life.

Americans would never consent to a government directive that all citizens carry a device that broadcast, in real time, their physical location and archived that information in repositories that could be shared among powerful, faceless institutions. Instead, Americans have been lulled into doing it voluntarily by misleading companies.

If a mobile phone is turned on, chances are its location is collected in a spreadsheet somewhere. What does it feel like to see that archive? We went to Pasadena to find out.

A home in Pasadena, Calif.

Take away the temperate, cloudless days, the 90,000-plus people who pack the Rose Bowl at the start of each year and the imposing presence of the San Gabriel Mountains to the north, and Pasadena could be anywhere. Which is, in part, why we chose Pasadena. The data doesn’t discriminate — it’s collected from every town and city in America. Situated 11 miles northeast of downtown Los Angeles and in the county of the same name, Pasadena is both of the city and not. Hollywood celebrities live there, but mostly to escape the crush of the Greater Los Angeles sprawl.

The city changes by the block. Palm-tree-lined streets with manicured lawns give way to suburban sprawl, drive-through liquor stores and laundromats. There are wildfires and gentrification. NASA and Caltech map the depths of the universe from here, while the public school district tries to provide a soft landing for a large influx of foster children.

Dan Paige, a Los Angeles County sheriff's deputy, has to look after all of it. As a member of the city’s Homeless Outreach, Search and Rescue, and the Community Emergency Response Team, he’s accustomed to being the person doing the tracking. But without his knowledge a series of apps on his phone had been silently, scrupulously relaying his location. When we emailed to say we were in town and had a map of his movements, Mr. Paige agreed to meet. He didn’t bother providing the station’s address. “Hopefully with that data you have, you can track my exact location,” he wrote.

A number of apps on Dan Paige’s phone tracked his movements without his knowledge.

Mr. Paige took over managing the Sheriff’s Station social media accounts in 2012, and so he carries two phones and an iPad most of the time. In a dimly lit room where we met, he drummed his fingers on his county-issue iPhone 6 and let out a resigned laugh as we showed him a detailed map of his movements over a few months: shuttling to the dry cleaners, then to lunch downtown followed by a stop at Search and Rescue headquarters and finally to a E.M.T. training at a Glendale community college. When we showed him the thick red lines drawing a direct route from the police station to his home, he winced.

“It is a little surprising,” he confessed. As a law enforcement officer, he was concerned about possible threats against him and his family. In his line of work, any record of his home, as well as of the stores and restaurants he frequents, is a vulnerability.

Mr. Paige is not a stranger to technology and privacy. He meticulously strips photos of their metadata before posting them to the sheriff’s department’s Twitter or Facebook accounts. He checks his permissions and helps educate fellow officers. But though he turns location services off on most of his apps, he’s aware that it takes only one slip-up to transmit his exact coordinates — like everyone, he’s only as secure as the weakest link in his chain of downloaded apps. “Whenever you agree to an app, there's those eight pages of two-point font to read and, yeah, I'm guilty of not reading — just hit ‘accept’ and roll the dice,” he said.

As they go about their daily lives, many Pasadena residents we spoke with, like the rest of us, frequent locations whose populations for one reason or another could be vulnerable — because they attend mosques or synagogues or work at secure facilities, like NASA’s Jet Propulsion Laboratory. We plucked one scientist at the lab out of the data, and when we tracked him down in real life and explained how we did it, he was alarmed. “Somebody who might want to get some information from [the lab] for instance, they might target me,” the scientist told us. “This will be a treasure trove for any spying agency, I would presume.” He asked that we preserve his anonymity in this story.

Smartphone apps buried in the pockets of unsuspecting Americans track movements everywhere, from motels to workplaces to homes to gas stations.

For Mr. Paige, seeing his location map laid out before him crystallized the risks to the community he has sworn to protect. He mused about the judges he knew in town, the prosecutors, the Hollywood celebrities and even the clergy whom someone might want to target. “If you were to compile a list of all the people that you feel could be vulnerable, it would probably be quite a few groups,” he told us.

All of it seemed, to him, more than a little out of control. “You have that feeling of it being out of your hands,” he said.

Among the most sensitive and vulnerable populations under Mr. Paige’s guard is the student body at John Muir High, a labyrinth of classrooms tucked against the San Fernando Freeway. When we arrived, the din from a nearby on-ramp was drowned out by the Muir drumline, which was putting the finishing touches on a routine for the playoff football game against Chaffey High School that evening. The principal, Lawton Gray, was presiding over it all, wearing a Mustangs T-shirt for the occasion.

At Muir, 79 percent of the students are listed by the Pasadena school district as “socioeconomically disadvantaged,” and Dr. Gray, who is fiercely protective of the kids, has no shortage of concerns. He does home visits to help students who are struggling with their school work or their family lives.

We went into the school, sat down with Dr. Gray at a table in his office and pulled up the dataset for John Muir High — roughly 80 cellphones pinging across a six-month period. His eyes widened and he put his elbows on the table for a closer look at the laptop screen. “Wait, they’re tracking individual cell phones? Oh, that’s scary,” he said. His eyes intensely scanned the screen. At first, he wasn’t sure what was in front of him. He stopped on a particular clustering of pings, peppered across Muir High School and the surrounding area. “Wait. This isn’t just everybody? This is for one person?” Yes, we told him. His voice went hushed. “Oh, shit.”

After a minute, he exhaled, and referred to a certain movie from 20 years ago that we also find ourselves thinking a lot about these days. “This is almost like ‘Enemy of the State,’” he said.

Lawton Gray, a high school principal, was startled to learn that people in his school were being tracked.

His thoughts went to the kids he knew who were having trouble with an abusive parent. “I just think about those families,” he said, letting out a short, exasperated sigh. “If there's child abuse or there's something going on and this parent has access to find out where this kid is even though they're not supposed to. That's what bothers me the most. Because I do know those situations.”

Many parents probably aren’t aware of this, but there are only weak rules and regulations prohibiting the location tracking of minors. Many terms-of-service agreements for apps prohibit people younger than 13 from creating accounts, but it’s really up to the kids and their families to enforce such rules. And with technology now everywhere in the classroom — much of it, like laptops, provided by some school districts — parents may not be aware how connected their children really are.

Dr. Gray zoomed out to see one device — very likely carried by a Muir student — and its lengthy data trail, a tangle of lines traversing the greater Los Angeles area. “There are no valid reasons that someone can tell me right now as to why they need to collect this data for people that are under 18 years old,” he said.

John Muir High School in Pasadena. Currently there are only weak rules and regulations prohibiting the location tracking of minors.

Paging through an entire city’s location data is disorienting. Initially, there’s the surprise at the ease of pulling needles out of the digital haystack. Draw a box around any given location, isolate a date or time and voilà — the bird’s-eye details of a life sprawl out before you. The first thing to notice is the granularity — precise movements, sometimes down to the inch. The precision is what feels most unnerving. Watching employees move from the cafeteria to their office and then idling in the parking lot feels less like a justifiable marketing insight than it does a pillar of the panopticon.

At the spreadsheet level, the notion of location tracking is abstract, almost a thought experiment. Corporations, hungry for Big Data, view mapping every move as an aggregation. But as you drive through Pasadena’s quiet sun-drenched streets, the surveillance becomes real. From this vantage, a location data map of Pasadena — or any town — takes on a darker quality. Each device and its pings are a detailed diary of a given day and also a dossier: intelligence collected on neighbors, parishioners or a fellow traveler in the produce section of the grocery store. Sanctified spaces like synagogues, churches and mosques are transformed from sacred gathering places into revealing data points. But such data are a blunt instrument, an inference or educated guess as to one’s identity. Show up someplace once and you’re forever associated with it in a database someplace, context be damned. We saw single visits to spaces where patrons probably thought their trip was lost to time and masked in the cover of night: a stroll into the Church of Scientology storefront, a late-night stop at a massage parlor. Now, forever, those visits are recorded in a database and often tied directly to a home address, viewable by anyone with access.

The collective nature of privacy has even made its way to local law enforcement. “It’s a concern for everybody,” John Perez, Pasadena’s chief of police, told us. He suggested a leak of such data could even turn neighbors against one another. “It’s going to start destroying relationships with families and people. At the end of the day, we’re going to be destroyed by it — and can we put it back together?”

Americans don’t have the vocabulary to adequately describe the experience and pervasiveness of digital surveillance. When we showed up on doorsteps, laptop in hand to inform people that their movements had been captured, sold and eventually supplied to us, many didn’t know what to make of it. Shocked? In theory, yes. And yet many also assumed they’d signed their data away long ago. Upset? Sometimes. They felt violated, but what could they really do about it? They were, when we visited them, alive and well, so how bad could it be? Many tried to describe a feeling but were unable to find the right words.

“I definitely don't like it,” Linda Keavy, a schoolteacher, told us as she stood on her doorstep one Sunday afternoon. “I don't know why they need that. And I don't know, I kind of get frustrated in that everything is about someone making money off of everything.”

“As sad as it is, it's kind of expected, I think,” said Luis Chavez, an emergency-room technician. “I'm sure a lot of people don't know that, they're just downloading some candy app, they have no idea.” Mr. Chavez traced his data path and rattled off explanations for the pings. A trip to see a cousin. Commutes to the hospital. A few trips to the Subaru dealership where he bought his car.

Luis Chavez’s data recorded his trips to work and to see family.

Mr. Chavez, like others we spoke to, seemed mostly unconcerned about himself but worried more about others, like the patients who come into his emergency room and might be anxious about their privacy, which in theory is protected by the Health Insurance Portability and Accountability Act. When we asked him what he’d say to companies that collected the information, he was at a loss for words. “I’m just wondering, where does it go? It's too late to reclaim it now — it's just permanently out there. I don't know what I'd say.”

When confronted with their digital trail, people can get defensive. On doorsteps across Pasadena, people assured us they’d already taken steps to protect themselves. They'd heard about Facebook’s Cambridge Analytica scandal, and they notice when they’re followed around the internet with targeted ads. They weren’t surprised, but many couldn’t suppress a sheepishness when we explained that we’d been looking at them, as if they’d done something wrong or been exposed for sloppy digital hygiene. Despite our assurances that there’s little way to escape at least some location tracking, many seemed to blame themselves for getting caught up in a dataset they had no idea existed.

Some people we identified just shrugged off the news. They saw themselves as unimportant, and so they thought there was little risk anyone would ever go to the trouble of de-anonymizing their location data and using it against them. Some simply couldn’t imagine harm coming from such information, even when the data exposed the most personal corners of their lives.

Like most digitally savvy folks, Ed Honowitz, a former small-business owner, figured that precious pieces of his data were ricocheting around unknown servers. He told us that while the location map trail in our dataset was alarming to see, he wasn’t quite surprised. “It's not like ‘Oh my God, I had no idea this existed.’”

One man we identified in the data — M. — was so concerned about his privacy that he insisted we not identify him by name and meet him not at his house, which is in a gated community, but at his place of worship. Of all the data trails we tracked in the region, his told the most poignant story. It showed a series of visits to a hospital by two phones, one of which eventually disappeared from the data. The pings chronicled the progression of an illness that eventually claimed the life of M.’s wife.

He squinted at the information spread out on the laptop before him. The movements of his late wife were cherished memories for him. Did it seem wrong that they could also be corporate intelligence to a marketer? M. just shrugged. The trials of her illness, as painful and private as they were at the time, were summed up in a public obituary. Ultimately, he argued, the data was already out in the world. It had already traveled so far. So what if it was now staring back at him through the screen?

Robert Howell, a professor of philosophy at Southern Methodist University, has identified what he calls the Peeping Tom Effect to express the indifference many people feel toward data surveillance. He says we have a visceral reaction only “when we think about living, breathing agents observing our private lives.” It just doesn’t feel like such a personal violation when “corporations are collecting the same information and storing it on their computers.”

This psychological bias in favor of faceless surveillance may explain why Amazon’s Alexa smart speaker faced such a backlash after reports revealed that Amazon hired thousands of people to listen to the recordings. Few people had seemed bothered that Amazon could store conversations for eternity and using them for targeted advertising or other profitable ends. That feeling curdled only when Alexa users learned that real people were listening in.

It’s also possible that many people just feel as if they never had that much privacy to begin with, even before the era of mobile phones and ubiquitous corporate surveillance. Some security and privacy researchers, like Munish Walther-Puri, argue this is the reason average citizens are resigned to invasive practices like location tracking: “What is the value of privacy if you never felt like you had it to begin with?”

And yet the data is ours. It comes from the phones we bought, on mobile networks we pay to use. It chronicles our movements and our lives. It may be used to manipulate our behavior by nudging us toward a particular purchase or political candidate. It may be leaked or hacked or bought or sold to bad actors and abused. If that happens, we, not the corporations who hold our data, will suffer personal consequences.

Data is collected from every town and city in America, including Pasadena.

Sitting at her kitchen table, Margie Homer couldn’t stop following her past self. “That was a birthday party,” she said hovering a cursor over the details of a Saturday afternoon nearly three years ago. Her two cats nuzzled at our feet as she leaned in toward our laptop. “That's the cafeteria, and that's the building that I primarily work in.” She was gesturing toward a sprawling complex of buildings that make up NASA’s Jet Propulsion Laboratory, a secure facility roughly the size of a university where Dr. Homer, a chemist, works on projects for space stations.

Dr. Homer is no Luddite. At J.P.L., she’s surrounded by state-of-the-art technology and an army of number crunchers and data miners. Privacy warnings have rubbed off on her — enough that she has resisted the constant pleas of her pre-teenage kids for a smartphone. Aside from the occasional tracking mandated by her favorite guilty pleasure, “Pokémon Go,” Dr. Homer assumed she’d been a good steward of her location data.

She grabbed her Android off the table and started sifting through her apps, starting with those whose location permissions were set to “allowed all the time."

Margie Homer felt betrayed by the apps tracking her movements.

CVS. Google Maps. Google search. Google V.R. services, which Dr. Homer didn’t recall giving location permissions. Google Wifi and Chrome. Ikea. Amazon. AMC. Theaters. Pokémon Go. She paused on an app from her school district that she hadn’t realized had been hoovering up location data. “This is the problem with putting all this technology into people's hands when they don't really understand what's going on,” she said. “I'm not stupid. In a sense, I saw it coming. People talk about it at work all the time. But it's a completely different thing when someone shows you a map.”

Dr. Homer was outraged and frustrated. Scrolling through visits to friends and family, she worried that maybe her data might somehow reveal the information of those closest to her. She remembered political protests she attended — was her phone betraying activists around her? Staring at the data, it became easy to see what people frequently misunderstand: Privacy isn’t just an individual matter. It’s a collective concern. Dr. Homer’s location wasn’t just hers but was also intertwined with that of every person she’d encountered.

Consent is murky. Technically, each ping is collected legally, with the express consent of the device holder; apps can’t collect GPS data unless you allow them to via a pop-up screen. But of the dozens of Pasadena residents we spoke with — even those unfazed by the detail of the data — none felt as though they’d consented to this level of collection. “Undoubtedly the whole industry benefits from the passivity of people, just not caring that much about what happens, or understanding, or worrying about it,” said Mr. Honowitz, the former small-business owner we surprised with his data on his front porch.

“If these companies actually walked us through their terms of service on these apps in a meaningful way, people would say: ‘This is insane. I don't want to give you the right to do this,’” said Patrick Cahalan, a Pasadena School Board member.

Collecting every scrap of our lives via smartphones is framed as a trade-off. If companies know where you are, they can serve you better information, like a personalized ad or a list of coffee shops near you. Pooling the data is even more useful. Companies can see trends, like traffic patterns, which may result in a faster commute. That’s a persuasive argument.

Location tracking has always been an abstract idea. Consumers could never see behind the scenes and into the data.

What happens when Americans parse the information companies actually collect on them? They begin to evaluate the true cost of their digital conveniences. For Dr. Homer the cost was this: the location of her home, her parents’ house, her office, the site of a date and even her kids’ favorite stalls at an annual holiday carnival. And while she’s not entirely sure which app or apps was the culprit, she thinks it’s entirely possible she traded it all for a few coupons for a reduced price on soup, the benefit she received for giving location permission to a hastily downloaded app.

Dr. Homer is lucky. What separates her from the tens of millions of us who’ve traded our information is that she has seen the full exchange of values. Unlike the rest of us, she knows, down to the data point, the cost of her services rendered. Is it really worth it? That’s a question not just people in Pasadena, but all of us, need to ask ourselves.