Image: danielsolove.substack.com
The Story
Tower dumps expose private movements, but the constitutional answer turns on what investigators sought and saw in each warrant.
Chatrie establishes that location data can implicate a reasonable expectation of privacy, so Fourth Amendment scrutiny applies. It does not automatically follow that every tower dump fails. Courts may examine the warrant’s geographic and temporal scope, the information exposed to investigators, probable cause, and minimization measures rather than impose a categorical ban.
- For courtsThe central task is to define the search by its practical exposure, not simply by the number of records held by a carrier.
- For policeBroad requests face stronger scrutiny after Chatrie, especially when they identify people only after collecting everyone’s location data.
- The Supreme Court recognized a reasonable expectation of privacy in geolocation data obtained through a geofence warrant, making the Fourth Amendment applicable.
- A leading Fourth Amendment analysis argues that digital scans should be judged primarily by filter settings and the information exposed to human observation, not merely by database size or raw output.
- Tower dumps may be assessed through the warrant’s particular facts and safeguards rather than treated as automatically unconstitutional in every form.
Source mix
3 of 7 institutional
- 3 Journals & institutions
- 1 Groups & independent outlets
- 1 Forum, video, personal
- 2 Other / unclassified
Deeper Insight
Nearly 1,700 phones went into one police dragnet. Tower dumps turn being nearby into grounds for investigation.
Nearly 1,700 phones were swept into a California murder investigation because they connected to towers along a highway. That flips the Fourth Amendment’s usual order: police collect everyone’s location first, then hunt for a suspect. The Ninth Circuit could draw a line here, or let mass location searches become routine by approving them one case at a time.
- What it could changeA strict ruling could force police to start with a person, not a map full of strangers.
- How it touches todayEvery phone near a crime scene can already become part of the investigation.
- Our futureOrdinary movement could become a permanent source of suspicion, one tower dump at a time.
- EFF and the ACLU argue that tower dumps are overbroad general warrants because they compel providers to disclose every phone’s location in a defined area and time.
- The Spurlock tower dump produced location data for nearly 1,700 unique phones, illustrating how a targeted investigation can begin with a mass collection of bystanders’ data.
- A Mississippi federal judge held that no tower-dump warrant can satisfy the Fourth Amendment because the technique identifies no target phone or person and can produce thousands of records.
Sources · 7
- 3 Journals & institutions
- 1 Groups & independent outlets
- 1 Forum, video, personal
- 2 Other / unclassified
What do these mean?
- Journals & institutions. Published in a peer-reviewed journal, or from a university, government body, court or other institution.
- Groups & independent outlets. Think tanks, advocacy groups and independent outlets or blogs, on any side of the question. They publish with a point of view.
- Forum, video, personal. Forums, social posts, video, blogs and personal accounts.
- Other / unclassified. A site we have not classified yet. This says nothing good or bad about it.
Featured · Primary source · storage.courtlistener.com
____________________ No. 3:25-CR-38 IN RE FOUR APPLICATIONS FOR SEARCH WARRANTS SEEKING INFORMATION ASSOCIATED WITH PARTICULAR CELLULAR TOWERS A/K/A TOWER-DUMP WARRANTS ____________________ ____________________
Primary document
____________________ No. 3:25-CR-38 IN RE FOUR APPLICATIONS FOR SEARCH WARRANTS SEEKING INFORMATION ASSOCIATED WITH PARTICULAR CELLULAR TOWERS A/K/A TOWER-DUMP WARRANTS ____________________ ORDER ____________________ Before CARLTON W. REEVES, District Judge. Digital surveillance has been a huge boon
Read sourceAnalysis · eff.org
We’re Asking the Ninth Circuit to Hold Reverse Location Warrants Categorically Unconstitutional
Think tank or advocacy group
Yesterday, along with the ACLU, EFF filed an amicus brief in the Ninth Circuit court of appeals in United States v. Spurlock , a case involving a “tower dump” warrant. These overbroad warrants require cellular providers to turn over location data about every phone in a given area at a given time. This is the first such case to be heard by a federal appeals court since the US Supreme Court ruled th
Read sourceAnalysis · arnoldporter.com
Signal Lost: Mississippi Federal Court Declares Tower Dump Warrants Unconstitutional | Enforcement Edge | Blogs | Arnold & Porter
Other
Signal Lost: Mississippi Federal Court Declares Tower Dump Warrants Unconstitutional | Enforcement Edge | Blogs | Arnold & Porter August 11, 2026 # Signal Lost: Mississippi Federal Court Declares Tower Dump Warrants Unconstitutional By Ryan T. Fenn Lee M. Cortes, Jr. On August 5, 2026, U.S. District
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