Real-Time Bidding: The Surveillance System You're Already In
Every time you open an app that serves ads, your phone fires your GPS coordinates, device identifiers, and behavioral data to hundreds of ad exchanges simultaneously — in milliseconds. This is called real-time bidding (RTB). It was designed to let advertisers bid on your eyeballs. It accidentally created a global surveillance infrastructure. Data brokers sit downstream: they buy that stream of location data from ad exchanges, aggregate it, and resell it. Government agencies — including CBP and ICE — buy from data brokers. No search warrant. No court order. No probable cause required. They simply pay for it.
Your Location History Is a Confession They Can Buy
- Where you sleepConsistent nighttime GPS clusters reveal your home address even if you've never shared it with any service.
- Places of worshipAttendance patterns at mosques, churches, synagogues, and other religious sites — tracked over months or years.
- Medical facilities visitedClinics, reproductive health centers, addiction treatment facilities, and HIV specialists — all identifiable from location pings.
- Protest attendanceYour phone at a protest means your location was logged, sold, and potentially purchased. There is no retroactive erasure.
- Who you live withDevices that regularly co-locate overnight can be inferred as household members or close associates — even across different accounts.
- Immigration status inferencesLocation patterns near border checkpoints, immigration courts, and consulates can be used to make inferences about immigration status or activity.
Why This Doesn't Require a Warrant — Yet
The Fourth Amendment requires the government to obtain a warrant before conducting a search. But buying data commercially is, in the government's view, not a "search" at all.
The government's argument rests on the third-party doctrine: if you voluntarily share information with a third party — an app, a service — you lose your Fourth Amendment protection against the government obtaining that information. You "chose" to use an app that served ads. Therefore you "consented" to the data flow. Therefore the government can buy it without a warrant.
In Carpenter v. United States (2018), the Supreme Court drew a line. It ruled that obtaining 7 or more days of historical cell-site location records from a carrier does require a warrant — because such records are comprehensive, precise, and people don't truly consent in any meaningful sense to sharing them with the government. Carpenter was a significant win for digital privacy.
The gap: Carpenter covered carrier data. Ad tech location data comes not from carriers but from apps and the commercial data-broker ecosystem. Courts have not yet ruled on whether Carpenter's logic extends to broker-purchased ad data. That question is open.
It is an open loophole. Congress has not closed it. Courts haven't ruled on it. Government agencies are exploiting it right now.
Five Specific Actions — With Exact Steps
Android:Settings → Privacy → Ads → Delete advertising ID
iPhone: Settings → Privacy → Location Services — set to "Never" for any app that doesn't require location to function. Deny "Precise Location" even where you allow location at all.
Android: Settings → Location → App permissions — review each app.
Signal Protocol: end-to-end encrypted by default for all messages and calls.
Metadata: Signal does not log who you message, when, or how often on their servers.
Recommended: ProtonVPN (Swiss-based, no-log policy, open source, free tier available).
A VPN encrypts your traffic from your carrier and masks your IP address.
Airplane mode disables all radio transmission: cell, Wi-Fi, Bluetooth, and GPS simultaneously.
To be safe, also disable Wi-Fi and Bluetooth individually — on some devices airplane mode does not fully disable these.