CBP tapped into the online advertising ecosystem to track peoples’ movements
US Customs and Border Protection’s use of commercial ad-tech location data to monitor people’s movements is prompting renewed alarm over how cheaply and widely such data can be bought and repurposed. Commenters debate how accurate and individually identifying this bidstream data really is, but broadly agree that neither governments nor ad companies should be able to track individuals so easily through phones, apps, and carriers. Many argue that only stronger legal limits on data collection, resale, and government procurement—alongside personal measures like ad blocking, VPNs, and minimal app use—can meaningfully curb this kind of surveillance.
Advertising Data as Surveillance Infrastructure
- Many see CBP’s use of ad-tech data as inevitable once the private surveillance ecosystem existed.
- Concern that systems built for marketing are now turnkey tools for state surveillance and for any actor who can buy data.
- Some note this can also be used “for good” (e.g., investigating high-profile offenders) but still view the system as fundamentally dangerous.
How Accurate/Useful is Ad Location Data?
- One viewpoint: bidstream location data is noisy, IP-based, poorly deduplicated, and better for pattern analysis than tracking individuals; cited examples where agencies struggled to use it effectively.
- Counterpoint: “hard” ≠ “impossible”; deanonymization research and commercial services show that fusing datasets can re-identify people; hyperlocal geofencing in practice violates self-imposed limits.
Cell Networks, Devices, and Location Privacy
- Recognition that phones constantly talk to cell towers; this data can be precise and has historically been sold by carriers.
- Debate over whether powered-off phones still communicate; some argue this underpins “Find My,” others are skeptical or note this isn’t accessible to ad networks.
- Some recommend hardware kill switches, removable batteries, or burner phones; others see this as impractical or “tinfoil hat” territory.
Mitigations and Personal Opsec
- Strong support for aggressive ad blocking: browser extensions, DNS sinkholes (Pi-hole, NextDNS), VPNs, and avoiding ad-supported apps.
- Suggestions: use privacy-focused MVNOs, private DNS, anti-tracking browsers, minimal app installs, no social media.
- Skeptics label some of this “privacy theater” given carrier/NSA visibility, but others argue it still meaningfully reduces commercial tracking and profiling.
Law, Regulation, and Government Access
- Discussion of carriers’ location data vs ad data: buying from brokers can bypass warrant requirements (third-party doctrine).
- Some argue US contracts nominally exclude US persons, but implementation and enforcement are questioned.
- Debate on whether “European-style” privacy laws would help; consensus that collection, resale, and government procurement all need explicit limits plus real enforcement.
Ethics of Ad-Tech and Tech Work
- Frustration at programmers and ad-tech firms building systems that work against users’ interests.
- Others stress structural incentives and management decisions rather than blaming individual developers.
- Broader pessimism about social norms eroding and regulation lagging behind increasingly intrusive data practices.