How law enforcement's ability to track people via commercially available data blurs the line between investigative due diligence and warrantless surveillance
Agencies' growing use of purchased data without warrants raises new legal questions — In January 2020, a 14-year-old girl …
Context & Ripple Effects
The Wall Street Journal's reporting lands mid-arc on a question Congress has been pulling at since late 2020, when the DHS inspector general opened a probe into the department's practice of buying brokered cellphone data to track people without warrants following a request from Democratic senators. The paper trail since then has moved from federal agencies to the supply side: Mobilewalla's letter to Sen. Wyden confirming it was the source of some of the data used by DHS, the IRS, and the US military made clear that a single commercial broker sits behind multiple agencies' tracking programs.
What changed today is scope, not kind — the same pattern now documented at the state and local level, where an investigation found the Fog Reveal tool letting small departments search records from over 250 million devices, at times without warrants. A later review of 115 warrants for Google location and search data across five states showed even the warrant-based channel drifting toward routine use in nonviolent cases, so the purchased-data shortcut compounds a broader normalization of bulk location access.
First-order effects
- Federal users of Mobilewalla-sourced data — DHS, the IRS, and the military — are already under the DHS inspector general's warrantless-tracking probe, and Mobilewalla itself is now publicly identified as the broker behind them, inviting congressional subpoenas or restrictions aimed at its contracts.
- Local police using tools like Fog Reveal face immediate exposure of practices run without warrants or oversight, forcing departments to defend purchases their own counsel may have never reviewed.
Second-order effects
- Courts and legislatures get pushed toward deciding whether buying data from a broker legally sidesteps the Fourth Amendment warrant requirement — a ruling either way reshapes every agency contract in the space.
- Data brokers face procurement bans and disclosure demands from individual states and agencies, splitting the market between vendors willing to sell to law enforcement and those positioning for privacy-sensitive commercial buyers.
Third-order effects
- If the pattern holds, surveillance migrates structurally from the courtroom (subpoenas, judges) to the marketplace (contracts, vendors), meaning regulation must eventually target the brokerage layer — who may aggregate and resell device data at all — rather than each agency's conduct.
- Oversight bodies like inspectors general become the de facto check on this channel first, setting precedents that determine whether warrant-free purchased data becomes standard investigative tooling or a scandal-driven carve-out.
The trend: Government tracking is shifting from a court-warrant regime to a commercial one, where agencies buy device data from brokers and the legal fight moves from judges' chambers to procurement offices.