Illinois Geofence Warrants: How Police Use Your Location Data

 Posted on October 09, 2025 in Criminal Defense

In Illinois, as with many states, prosecutors and law enforcement agencies are using "geofence warrants" to investigate crimes. Unlike traditional warrants that target a specific suspect, geofence warrants cast a much wider (digital) net. A geofence warrant requires a company like Google to turn over location data from every device within a defined timeframe and area.

Obviously, law enforcement sees this as a powerful investigative tool, but others warn that geofence warrants not only threaten privacy but also risk pulling innocent people into criminal investigations. If you were questioned about a criminal offense based only on a geofence warrant, it is essential to speak to a knowledgeable Joliet, IL criminal defense lawyer as quickly as possible.

Understanding Geofence Warrants

A geofence warrant identifies individuals who were at a specific location during a specified time frame related to a crime. Law enforcement defines a virtual boundary, or geofence, around a crime scene, then asks major companies to provide a list of devices that were in that area during that time.

The initial data is anonymous, requiring law enforcement to obtain a second warrant and conduct a second phase to "unmask" the devices and obtain the subscriber information. Geofence warrants could violate the requirement in the Fourth Amendment for particularity, although courts have been split about the constitutionality of geofence warrants, and the Supreme Court has yet to issue a definitive ruling.   

How Are Companies Responding to Geofence Warrants?

Companies have responded to geofence warrants differently. Google was the primary target of geofence warrants, thanks to its Sensorvault database that stored massive quantities of user location data. Google has almost ended its ability to comply with geofence warrants by making significant policy changes, which changed how the company stores location data and increased automatic deletion periods. Rather than being stored on Google’s servers, most location history is now stored on users’ devices.  

Apple has stated that it does not collect the type of specific location data required to fulfill geofence warrants, effectively refusing to comply. Other tech companies vary in their response to geofence warrants, although none were as frequently targeted as Google. Companies like Lyft, Uber, and Snapchat have complied with geofence warrants, but not in any coherent "make-a-policy-like" manner. Microsoft has stated it does not possess the kind of broad knowledge sought by geofence warrants.

What are the Risks of Geofence Warrants for Defendants?

A geofence warrant has the ability to catch innocent people up in a broad data sweep, causing these people to be investigated for a crime they had no part of. There is the very real fear that prosecutors and law enforcement will use geofence warrants to build circumstantial cases. There is also the real possibility of faulty location data and misinterpretation of that data by law enforcement.

What Are the Most Common Defenses Against Geofence Warrants?

Geofence warrants are very general, which violates the Fourth Amendment’s requirements both for probable cause and for particularity. This means that law enforcement must have probable cause that a specific person committed a specific crime. A geofence warrant is basically a "reverse search," which identifies every device passing through a specific location at a specific time, including those with no connection to the crime. Other common defenses against geofence warrants include:

• Geofence warrants violate the reasonable expectation of privacy
• While the prosecutor may argue that individuals have no expectation of privacy with information voluntarily shared with a third party, a defense attorney may counter that consent to location tracking is rarely voluntary or meaningful (Nobody reads the complex electronic agreements)
• The defense attorney may argue that the officer’s reliance on a geofence warrant cannot be considered reasonable due to the new technology.

Contact a Will County, IL Criminal Defense Lawyer

If you have been implicated in a crime as a result of a geofence warrant in Illinois, your case may be built on shaky constitutional grounds. A highly skilled Joliet, IL felony crimes attorney from Law Office of Eric J. Blatti, P.C. knows how to challenge overbroad warrants in court. Attorney Blatti is local to the Joliet area and has extensive experience, along with good relationships with judges and attorneys. To schedule your free consultation, call 815-744-2500.