CBP tapped into the online advertising ecosystem to track peoples’ movements
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.