We haven’t seen the end of invasive geofence warrants just yet, despite Google’s big announcement late last year that it was fundamentally changing how it collects location data. Today, EFF is filing an amicus brief in the Minnesota Supreme Court in State v. Contreras-Sanchez, involving a warrant that directed Google to turn over an entire month of location data in response to a geofence warrant. Our brief argues that warrant violates the Fourth Amendment and Minnesota’s state constitution.

Geofence warrants require a provider—almost always Google—to search its entire reserve of user location data to identify all users or devices located within a geographic area during a time period specified by law enforcement. This creates a high risk of turning suspicion on innocent people for crimes they didn’t commit and can reveal sensitive and private information about where individuals have traveled in the past. We’ve seen a recent flurry of court cases involving geofence warrants, and these courts’ rulings will set important Fourth Amendment precedent not just in geofence cases, but other investigations involving similar “reverse warrants” such as users’ keyword searches on search engines.

In Contreras-Sanchez, police discovered a dead body on the side of a rural roadway. They did not know when the body was disposed of and had few leads, so they sought a warrant directing Google to turn over location data for the area around the site for the previous month. Notably, Google responded that turning over the entire monthlong dataset would be too “cumbersome,” even though it covered only a relatively sparsely populated area. Instead, following the now-familiar “three-step” process for geofence warrants, Google provided police with location data corresponding to twelve devices that had entered the area over a single week period. Police focused in on one device, then sought identifying information on that device, leading them to the defendant.

EFF’s brief, filed along with the National Association of Criminal Defense Lawyers and the Minnesota Association of Criminal Defense Lawyers, argues that the geofence warrant acted as a “general warrant” akin to the practices of the British agents in Colonial America who were authorized to go house by house, searching for smuggled goods and evidence of seditious publications. As we write in the brief:

This general warrant allowed law enforcement to go Google account by Google account, searching each user’s private location data for evidence of an alleged crime. The same concerns that animated staunch objection to general warrants in the past are equally relevant to geofence warrants today; these warrants lack individualized suspicion, allow for unbridled officer discretion, and impact the privacy rights of countless innocent individuals. And, like the eighteenth-century writs of assistance that inspired the Fourth Amendment’s drafters, geofence warrants are especially pernicious because they also have the potential to affect fundamental rights including freedom of speech, association, and bodily autonomy. Neither the Fourth Amendment, nor Article 1, Section 10 of the Minnesota Constitution tolerate a warrant of this breadth.

Federal appeals court makes a serious misstep on geofence warrants

Meanwhile, in the leading federal geofence case, United States v. Chatrie, the federal Court of Appeals for the Fourth Circuit issued a seriously misguided opinion earlier this month, holding that a geofence warrant covering a busy area around a bank robbery for two hours wasn’t even a Fourth Amendment search at all—meaning that the police wouldn’t necessarily need a warrant to get access to all of this sensitive location data. The two-judge majority opinion effectively ignores the impact of the U.S. Supreme Court’s landmark Fourth Amendment location data case, Carpenter v. United States, and similarly tries to distinguish the Fourth Circuit’s own important precedent in Leaders of a Beautiful Struggle v. Baltimore Police Department. In the majority’s view, in order to be a search protected by the Fourth Amendment, the government must collect a significant amount of location data over a long period of time, and the two-hour period at issue in Chatrie simply wasn’t long enough to interfere with individuals’ reasonable expectation of privacy in the “whole of their physical movements” the way longer surveillance was in Carpenter and Leaders.

But in a scathing, 70-plus page dissenting opinion, Judge Wynn dismantled these arguments, showing that Carpenter requires courts to look beyond formulaic applications of precedent and examine the actual character of the surveillance at issue. On nearly every metric, geofence warrants have the capacity to reveal just as, if not more, private and intimate associations than the tracking at issue in Carpenter. What’s more, Judge Wynn’s dissent demonstrated what we’ve argued in geofence cases across the country: These warrants violate the Fourth Amendment because they are not targeted to a particular individual or device, like a typical warrant for digital communications. The only “evidence” supporting a geofence warrant is that a crime occurred in a particular area, and the perpetrator likely carried a cell phone that shared location data with Google. For this reason, they inevitably sweep up potentially hundreds of people who have no connection to the crime under investigation—and could turn each of those people into a suspect.

Chatrie’s lawyers are petitioning the entire Fourth Circuit to review the case, and we’re hopeful that the Chatrie panel opinion will be overturned by the full court en banc. We’ll be filing another amicus brief supporting Chatrie’s petition. Stay tuned for that and for the ruling from the Minnesota Supreme Court in Contreras-Sanchez. 

Dozens of policing agencies are currently using cell-site simulators (CSS) by Jacobs Technology and its Engineering Integration Group (EIG), according to newly-available documents on how that company provides CSS capabilities to local law enforcement. 

A proposal document from Jacobs Technology, provided to the Massachusetts State Police (MSP) and first spotted by the Boston Institute for Nonprofit Journalism (BINJ), outlines elements of the company’s CSS services, which include discreet integration of the CSS system into a Chevrolet Silverado and lifetime technical support. The proposal document is part of a winning bid Jacobs submitted to MSP earlier this year for a nearly $1-million contract to provide CSS services, representing the latest customer for one of the largest providers of CSS equipment.

An image of the Jacobs CSS system as integrated into a Chevrolet Silverado for the Virginia State Police. Source: 2024 Jacobs Proposal Response

The proposal document from Jacobs provides some of the most comprehensive information about modern CSS that the public has had access to in years. It confirms that law enforcement has access to CSS capable of operating on 5G as well as older cellular standards. It also gives us our first look at modern CSS hardware. The Jacobs system runs on at least nine software-defined radios that simulate cellular network protocols on multiple frequencies and can also gather wifi intelligence. As these documents describe, these CSS are meant to be concealed within a common vehicle. Antennas are hidden under a false roof so nothing can be seen outside the vehicles, which is a shift from the more visible antennas and cargo van-sized deployments we’ve seen before.  The system also comes with a TRACHEA2+ and JUGULAR2+ for direction finding and mobile direction finding. 

The Jacobs 5G CSS base station system. Source: 2024 Jacobs Proposal Response

CSS, also known as IMSI catchers, are among law enforcement’s most closely-guarded secret surveillance tools. They act like real cell phone towers, “tricking” mobile devices into connecting to them, designed to intercept the information that phones send and receive, like the location of the user and metadata for phone calls, text messages, and other app traffic. CSS are highly invasive and used discreetly. In the past, law enforcement used a technique called “parallel construction”—collecting evidence in a different way to reach an existing conclusion in order to avoid disclosing how law enforcement originally collected it—to circumvent public disclosure of location findings made through CSS. In Massachusetts, agencies are expected to get a warrant before conducting any cell-based location tracking. The City of Boston is also known to own a CSS. 

This technology is like a dragging fishing net, rather than a focused single hook in the water. Every phone in the vicinity connects with the device; even people completely unrelated to an investigation get wrapped up in the surveillance. CSS, like other surveillance technologies, subjects civilians to widespread data collection, even those who have not been involved with a crime, and has been used against protestors and other protected groups, undermining their civil liberties. Their adoption should require public disclosure, but this rarely occurs. These new records provide insight into the continued adoption of this technology. It remains unclear whether MSP has policies to govern its use. CSS may also interfere with the ability to call emergency services, especially for people who have to use accessibility technologies for those who cannot hear.

Important to the MSP contract is the modification of a Chevrolet Silverado with the CSS system. This includes both the surreptitious installment of the CSS hardware into the truck and the integration of its software user interface into the navigational system of the vehicle. According to Jacobs, this is the kind of installation with which they have a lot of experience.

Jacobs has built its CSS project on military and intelligence community relationships, which are now informing development of a tool used in domestic communities, not foreign warzones in the years after September 11, 2001. Harris Corporation, later L3Harris Technologies, Inc., was the largest provider of CSS technology to domestic law enforcement but stopped selling to non-federal agencies in 2020. Once Harris stopped selling to local law enforcement the market was open to several competitors, one of the largest of which was KeyW Corporation. Following Jacobs’s 2019 acquisition of The KeyW Corporation and its Engineering Integration Group (EIG), Jacobs is now a leading provider of CSS to police, and it claims to have more than 300 current CSS deployments globally. EIG’s CSS engineers have experience with the tool dating to late 2001, and they now provide the spectrum of CSS-related services to clients, including integration into vehicles, training, and maintenance, according to the document. Jacobs CSS equipment is operational in 35 state and local police departments, according to the documents.

EFF has been able to identify 13 agencies using the Jacobs equipment, and, according to EFF’s Atlas of Surveillance, more than 70 police departments have been known to use CSS. Our team is currently investigating possible acquisitions in California, Massachusetts, Michigan, and Virginia. 

An image of the Jacobs CSS system interface integrated into the factory-provided vehicle navigation system. Source: 2024 Jacobs Proposal Response

The proposal also includes details on other agencies’ use of the tool, including that of the Fontana, CA Police Department, which it says has deployed its CSS more than 300 times between 2022 and 2023, and Prince George's County Sheriff (MO), which has also had a Chevrolet Silverado outfitted with CSS. 

Jacobs isn’t the lone competitor in the domestic CSS market. Cognyte Software and Tactical Support Equipment, Inc. also bid on the MSP contract, and last month, the City of Albuquerque closed a call for a cell-site simulator that it awarded to Cognyte Software Ltd. 

Our concerns about the selling and misuse of location data for those seeking reproductive and gender healthcare are escalating amid a recent wave of cases and incidents demonstrating that the digital trail we leave is being used by anti-abortion activists.

The good news is some states and tech companies are taking steps to better protect location data privacy, including information that endangers people needing or seeking information about reproductive and gender-affirming healthcare. But we know more must be done—by pharmacies, our email providers, and lawmakers—to plug gaping holes in location data protection.

Location data is highly sensitive, as it paints a picture of our daily lives—where we go, who we visit, when we seek medical care, or what clinics we visit. That’s what makes it so attractive to data brokers and law enforcement in states outlawing abortion and gender-affirming healthcare and those seeking to exploit such data for ideological or commercial purposes.

What we’re seeing is deeply troubling. Sen. Ron Wyden recenty disclosed that vendor Near Intelligence allegedly gathered location data of people’s visits to nearly 600 Planned Parenthood locations across 48 states, without consent. It sold that data to an anti-abortion group, which used it in a massive anti-abortion ad campaign.The Wisconsin-based group used the geofenced data to send mobile ads to people who visited the clinics.

It’s hardly a leap to imagine that law enforcement and bounty hunters in anti-abortion states would gladly buy the same data to find out who is visiting Planned Parenthood clinics and try to charge and imprison women, their families, doctors, and caregivers. That’s the real danger of an unregulated data broker industry; anyone can buy what’s gathered from warrantless surveillance, for whatever nefarious purpose they choose.

For example, police in Idaho, where abortion is illegal, used cell phone data in an investigation against an Idaho woman and her son charged with kidnapping. The data showed that they had taken the son’s minor girlfriend to Oregon, where abortion is legal, to obtain an abortion.

The exploitation of location data is not the only problem. Information about prescription medicines we take is not protected against law enforcement requests. The nation’s eight largest pharmacy chains, including CVS, Walgreens, and Rite Aid, have routinely turned over prescription records of thousands of Americans to law enforcement agencies or other government entities secretly without a warrant, according to a congressional inquiry.

Many people may not know that their prescription records can be obtained by law enforcement without too much trouble. There’s not much standing between someone’s self-managed abortion medication and a law enforcement records demand. In April the U.S. Health and Human Services Department proposed a rule that would prevent healthcare providers and insurers from giving information to state officials trying to prosecute some seeking or providing a legal abortion. A final rule has not yet been published.

Exploitation of location and healthcare data to target communities could easily expand to other groups working to protect bodily autonomy, especially those most likely to suffer targeted harassment and bigotry. With states passing and proposing bills restricting gender-affirming care and state law enforcement officials pursuing medical records of transgender youth across state lines, it’s not hard to imagine them buying or using location data to find people to prosecute.

To better protect people against police access to sensitive health information, lawmakers in a few states have taken action. In 2022, California enacted two laws protecting abortion data privacy and preventing California companies from sharing abortion data with out-of-state entities.

Then, last September the state enacted a shield law prohibiting California-based companies, including social media and tech companies, from disclosing patients’ private communications regarding healthcare that is legally protected in the state.

Massachusetts lawmakers have proposed the Location Shield Act, which would prohibit the sale of cellphone location information to data brokers. The act would make it harder to trace the path of those traveling to Massachusetts for abortion services.

Of course, tech companies have a huge role to play in location data privacy. EFF was glad when Google said in 2022 it would delete users’ location history for visits to medical facilities, including abortion clinics and counseling and fertility centers. Google pledged that when the location history setting on a device was turned on, it would delete entries for particularly personal places like reproductive health clinics soon after such a visit.

But a study by AccountableTech testing Google’s pledge said the company wasn’t living up to its promises and continued to collect and retain location data from individuals visiting abortion clinics. Accountable Tech reran the study in late 2023 and the results were again troubling—Google still retained location search query data for some visits to Planned Parenthood clinics. It appears users will have to manually delete location search history to remove information about the routes they take to visiting sensitive locations. It doesn’t happen automatically.

Late last year, Google announced plans to move saved Timeline entries in Google Maps to users’ devices. Users who want to keep the entries could choose to back up the data to the cloud, where it would be automatically encrypted and out of reach even to Google.

These changes would appear to make it much more difficult—if not impossible—for Google to provide mass location data in response to a geofence warrant, a change we’ve been asking Google to implement for years. But when these features are coming is uncertain—though Google said in December they’re “coming soon.”

Google should implement the changes sooner as opposed to later. In the meantime, those seeking reproductive and gender information and healthcare can find tips on how to protect themselves in our Surveillance Self Defense guide.