Skip navigation
CLN bookstore
× You have 2 more free articles available this month. Subscribe today.

Tracking Phones: Google as a Dragnet for the Police

by Bill Barton

The Google Sensorvault database has been used by law enforcement agencies on multiple occasions to obtain what are being called “geofence” warrants, which specify an area and period of time and require Google to provide information regarding the devices that were there.

According to, the warrant “labels [the devices] with anonymous ID numbers, and detectives look at locations and movement patterns to see if any appear relevant to the crime. Once they narrow the field to a few devices they think belong to suspects or witnesses, Google reveals the users’ names and other information.”

Catherine Turner, a Minnesota defense attorney who is handling a case involving the technique, said, “There are privacy concerns that we all have with our phones being tracked—and when those kinds of issues are relevant in a criminal case, that should give everybody serious pause.”

Gary Ernsdorff, a senior prosecutor in Washington state who has been involved with several cases utilizing geofence warrants, said, “It doesn’t pop out the answer like a ticker tape, saying this guy’s guilty. We’re not going to charge anybody just because Google said they were there.” said, “Technology companies have for years responded to court orders for specific users’ information. The new warrants go further, suggesting possible suspects and witnesses in the absence of other clues. Often, Google employees said, the company responds to a single warrant with location information on dozens or hundreds of devices. It is unclear how often these search requests have led to arrests or convictions because many of the investigations are still open, and judges frequently seal the warrants.

“The practice was first used by federal agents in 2016, according to Google employees, and first publicly reported last year in North Carolina. It has since spread to local departments across the country, including in California, Florida, Minnesota, and Washington.

“This year, one Google employee said, the company received as many as 180 requests in one week. Google declined to confirm precise numbers.”

A good example of just how many privacy and probable cause issues are raised by Sensorvault and the use of geofence warrants is the December 2018 arrest of warehouse worker Jorge Molina in a Phoenix suburb.

“Investigators also had other circumstantial evidence, including security video of someone firing a gun from a white Honda Civic, the same model that Mr. Molina owned, though they could not see the license plate or attacker. But after he spent nearly a week in jail, the case against Mr. Molina fell apart as investigators learned new information and released him. Last month [March 2019], the police arrested another man: his mother’s ex-boyfriend, who had sometimes used Mr. Molina’s car,” according to

“Mr. Molina, 24, said he was shocked when the police told him they suspected him of murder, and he was surprised at their ability to arrest him based largely on data. ‘I just kept thinking. You’re innocent, so you’re going to get out,’ he said, but he added that he worried that it could take months or years to be exonerated. ‘I was scared,’ he said.”

Google often does not provide information right away to law enforcement.

“The Google unit handling the requests has struggled to keep up, so it can take weeks or months for a response. In the Arizona investigation, police received data six months after sending the warrant,” said.

Jorge Molina, even though he was exonerated after spending about a week in jail, had his life disrupted in a major way by the consequences of his arrest. Arrested at his workplace, he subsequently lost his job. His car was impounded for investigation and then repossessed.

In a statement, Richard Salgado, Google’s director of law enforcement and information security, said that “the company tried to vigorously protect the privacy of our users while supporting the important work of law enforcement.” He added that it handed over identifying information only “where legally required.”

“Investigators who spoke with The New York Times said they had not sent geofence warrants to companies other than Google, and Apple said it did not have the ability to perform these searches. Google would not provide details on Sensorvault, but Aaron Edens, an intelligence analyst with the sheriff’s office in San Mateo, California, who has examined data from hundreds of phones, said most Android devices and some iPhones he had seen had this data available from Google.”

Current and former employees of Google have stated that the Sensorvault database was not designed for the needs of law enforcement, raising questions about its accuracy in some situations.

The use of geofence warrants raises novel legal issues, according to Orin Kerr, a law professor at the University of Southern California and an expert on criminal law in the digital age. These issues include:

(1) The privacy of innocent people scooped up in these searches. “Several law enforcement officials said the information remained sealed in their jurisdiction but not in every state,” reports. For instance, in Minnesota, the name of an innocent man was released to a local journalist “after it became part of the police record.”

(2) There are serious Fourth Amendment issues that have not been ruled upon by the U.S. Supreme Court, which ruled in 2018 that a warrant is required for historical data about a person’s cellphone location over the course of several weeks. But the Court has not ruled on anything like geofence, which harvests data from many people at once. Questions regarding the contours of probable cause with this type of warrant remain open.

In several cases reviewed by The Times, a judge approved the entire procedure in a single warrant, relying on investigators’ assurances that they would seek data for only the most relevant devices. Google responds to those orders, but Kerr said it was unclear whether multistep warrants should pass legal muster. “Some jurisdictions require investigators to return to a judge and obtain a second warrant before getting identifying information. With another warrant, investigators can obtain more extensive data, including months of location patterns and even emails,” according to

“Normally we think of the judiciary as being the overseer, but as the technology has gotten more complex, courts have had a harder and harder time playing that role,” Jennifer Granick, surveillance and cybersecurity counsel at the American Civil Liberties Union, told The Times. “We’re depending on companies to be the intermediary between people and the government.” 



As a digital subscriber to Criminal Legal News, you can access full text and downloads for this and other premium content.

Subscribe today

Already a subscriber? Login



Disciplinary Self-Help Litigation Manual - Side
CLN Subscribe Now Ad
Disciplinary Self-Help Litigation Manual - Side