Google tracked his bike ride past a burglarized home. That made him a suspect.

The email arrived on a Tuesday afternoon in January, startling Zachary McCoy as he prepared to leave for his job at a restaurant in Gainesville, Florida.

It was from Google’s legal investigations support team, writing to let him know that local police had demanded information related to his Google account. The company said it would release the data unless he went to court and tried to block it. He had just seven days.

“I was hit with a really deep fear,” McCoy, 30, recalled, even though he couldn’t think of anything he’d done wrong. He had an Android phone, which was linked to his Google account, and, like millions of other Americans, he used an assortment of Google products, including Gmail and YouTube. Now police seemingly wanted access to all of it.

“I didn’t know what it was about, but I knew the police wanted to get something from me,” McCoy said in a recent interview. “I was afraid I was going to get charged with something, I don’t know what.”

There was one clue.

In the notice from Google was a case number. McCoy searched for it on the Gainesville Police Department’s website, and found a one-page investigation report on the burglary of an elderly woman’s home 10 months earlier. The crime had occurred less than a mile from the home that McCoy, who had recently earned an associate degree in computer programming, shared with two others.

Now McCoy was even more panicked and confused. He knew he had nothing to do with the break-in ─ he’d never even been to the victim’s house ─ and didn’t know anyone who might have. And he didn’t have much time to prove it.

McCoy worried that going straight to police would lead to his arrest. So he went to his parents’ home in St. Augustine, where, over dinner, he told them what was happening. They agreed to dip into their savings to pay for a lawyer.

The lawyer, Caleb Kenyon, dug around and learned that the notice had been prompted by a “geofence warrant,” a police surveillance tool that casts a virtual dragnet over crime scenes, sweeping up Google location data — drawn from users’ GPS, Bluetooth, Wi-Fi and cellular connections — from everyone nearby.

The warrants, which have increased dramatically in the past two years, can help police find potential suspects when they have no leads. They also scoop up data from people who have nothing to do with the crime, often without their knowing ─ which Google itself has described as “a significant incursion on privacy.”

Still confused ─ and very worried ─ McCoy examined his phone. An avid biker, he used an exercise-tracking app, RunKeeper, to record his rides. The app relied on his phone’s location services, which fed his movements to Google. He looked up his route on the day of the March 29, 2019, burglary and saw that he had passed the victim’s house three times within an hour, part of his frequent loops through his neighborhood, he said.

“It was a nightmare scenario,” McCoy recalled. “I was using an app to see how many miles I rode my bike and now it was putting me at the scene of the crime. And I was the lead suspect.”

A powerful new tool

The victim was a 97-year-old woman who told police she was missing several pieces of jewelry, including an engagement ring, worth more than $2,000. Four days after she reported the crime, Gainesville police, looking for leads, went to an Alachua County judge with the warrant for Google.

In it, they demanded records of all devices using Google services that had been near the woman’s home when the burglary was thought to have taken place. The first batch of data would not include any identifying information. Police would sift through it for devices that seemed suspicious and ask Google for the names of their users.

Kenyon said police told him that they became particularly interested in McCoy’s device after reviewing the first batch of anonymized data. They didn’t know the identity of the device’s owner, so they returned to Google to ask for more information.

That request triggered the Jan. 14 notice the technology giant sent to McCoy, part of its general policy on notifying users about government requests for their information. The notice was McCoy’s only indication that police wanted his data.

Gainesville police declined to comment.

While privacy and civil liberties advocates have been concerned that geofence warrants violate constitutional protections from unreasonable searches, law enforcement authorities say those worries are overblown. They say police don’t obtain any identifying information about a Google user until they find a device that draws their suspicion. And the information alone is not enough to justify charging someone with a crime, they say.

Google geofence warrants have been used by police agencies around the country, including the FBI. Google said in a court filing last year that the requests from state and federal law enforcement authorities were increasing rapidly: by more than 1,500 percent from 2017 to 2018, and by 500 percent from 2018 to 2019.

“It’s a great tool and a great technology,” said Kevin Armbruster, a retired lieutenant with the Milwaukee Police Department, where he oversaw the use of high-tech investigative work, including geofence warrants.

Milwaukee police have used Google geofence warrants to solve an array of crimes, including homicides, shootings, a string of robberies and kidnappings and a sexual assault involving an abduction, he said. “I would think the majority of citizens in the world would love the fact that we are putting violent offenders in jail,” Armbruster said.

There have been very few court challenges to Google geofence warrants, mainly because the warrants are done in secret and defense lawyers may not realize the tool was used to identify their clients. One exception is an accused bank robber in Midlothian, Virginia, who is fighting the charge by arguing the geofence warrant used against him was illegal. That case is pending.

‘You’re looking at the wrong guy’

Once McCoy realized his bike ride had placed him near the scene of the crime, he had a strong theory of why police had picked his device out of all the others swept up by the warrant. He and Kenyon set out to keep them from getting any more information about him ─ and persuade them that he was innocent.

Kenyon said he got on the phone with the detective on the case and told him, “You’re looking at the wrong guy.”

For most of his life, McCoy said, he had tried to live online anonymously, a habit that dated to the early days of the internet when there was less expectation that people would use their real names. He used pseudonyms on his social media accounts and the email account that Google used to notify him about the police investigation.

But until then, he hadn’t thought much about Google collecting information about him.

“I didn’t realize that by having location services on that Google was also keeping a log of where I was going,” McCoy said. “I’m sure it’s in their terms of service but I never read through those walls of text, and I don’t think most people do either.”

Just before the start of his ordeal, he’d listened to a call-in radio debate about the Department of Justice’s fight with Apple over access to an iPhone left by a Saudi national who’d gunned down several people at an air base in Pensacola, Florida, in December. He remembered some callers saying they had no problem with law enforcement having access to phone data, arguing that people had nothing to worry about as long as they didn’t break the law. Now McCoy thought the callers weren’t considering predicaments like his.

“If you’re innocent, that doesn’t mean you can’t be in the wrong place at the wrong time, like going on a bike ride in which your GPS puts you in a position where police suspect you of a crime you didn’t commit,” McCoy said.

On Jan. 31, Kenyon filed a motion in Alachua County civil court to render the warrant “null and void” and to block the release of any further information about McCoy, identifying him only as “John Doe.” At that point, Google had not turned over any data that identified McCoy but would have done so if Kenyon hadn’t intervened. Kenyon argued that the warrant was unconstitutional because it allowed police to conduct sweeping searches of phone data from untold numbers of people in order to find a single suspect.

That approach, Kenyon said, flipped on its head the traditional method of seeking a search warrant, in which police target a person they already suspect.

“This geofence warrant effectively blindly casts a net backwards in time hoping to ensnare a burglar,” Kenyon wrote. “This concept is akin to the plotline in many a science fiction film featuring a dystopian, fascist government.”

Cleared by the same data

The filing seemed to give law enforcement authorities second thoughts about the warrant. Not long afterward, Kenyon said, a lawyer in the state attorney’s office assigned to represent the Gainesville Police Department told him there were details in the motion that led them to believe that Kenyon’s client was not the burglar. The state attorney’s office withdrew the warrant, asserting in a court filing that it was no longer necessary. The office did not respond to a request for comment.

Kenyon said that in a visit to his office, the detective acknowledged that police no longer considered his client a suspect.

On Feb. 24, Kenyon dropped his legal challenge.

The case ended well for McCoy, Kenyon said, but “the larger privacy fight will go unanswered.”

Even then, Kenyon wanted to make sure police didn’t have lingering doubts about McCoy, whom they still knew only as “John Doe.” So he met with the detective again and showed him screenshots of his client’s Google location history, including data recorded by RunKeeper. The maps showed months of bike rides past the burglarized home.

In the end, the same location data that raised police suspicions of McCoy also helped to vindicate him, Kenyon said. “But there was no knowing what law enforcement was going to do with that data when they got it behind closed doors. Not that I distrust them, but I wouldn’t trust them not to arrest someone.”

He pointed to an Arizona case in which a man was mistakenly arrested and jailed for murder largely based on Google data received from a geofence warrant.

McCoy said he may have ended up in a similar spot if his parents hadn’t given him several thousand dollars to hire Kenyon.

He regrets having to spend that money. He also thinks about the elderly burglary victim. Police said they have not made any arrests.

“I’m definitely sorry that happened to her, and I’m glad police were trying to solve it,” McCoy said. “But it just seems like a really broad net for them to cast. What’s the cost-benefit? How many innocent people do we have to harass?”