US Border Agency Used Online Ad Data to Track Phone Locations Without Warrants
CBP purchased commercial advertising data to monitor movements near the border, while Proton helped FBI identify a protester
The practice involves CBP buying location data harvested from smartphone apps through the online advertising ecosystem — the same data brokers use to target ads. By purchasing this data commercially rather than obtaining it through a court order, the agency effectively bypassed Fourth Amendment protections.
The revelation comes alongside a separate report that encrypted email provider Proton assisted the FBI in identifying a protester, raising fresh questions about the limits of privacy-focused services when confronted with law enforcement requests.
The combination of government agencies purchasing commercial surveillance data and privacy-oriented companies cooperating with law enforcement paints a picture of a surveillance landscape where traditional legal protections are increasingly insufficient.
Analysis
Why This Matters
The advertising data ecosystem has become a backdoor for government surveillance. Every app that collects location data potentially feeds into this pipeline, affecting billions of phone users.
Background
Commercial data purchases by government agencies have been controversial since at least 2020, when it emerged that the military and intelligence agencies were buying similar datasets. Courts have been slow to address whether these purchases constitute a search under the Fourth Amendment.
Key Perspectives
Privacy advocates argue this represents an end-run around the Supreme Court's 2018 Carpenter decision, which required warrants for cell-site location data. Government agencies counter that commercially available data is not subject to the same restrictions.
What to Watch
Pending legislation that would restrict government purchases of commercial data, and whether courts will extend Carpenter protections to cover advertising data.