Technique
Ad Network Tracking
Also known as: Online Behavioral Advertising, Surveillance Advertising, Cross-Site Tracking, Third-Party Tracking, Behavioral Targeting, Real-Time Bidding Surveillance
Advertising networks monitor user behavior across websites and apps via cookies, tracking pixels, device fingerprinting, and mobile ad identifiers (MAID) to build detailed profiles for targeted advertising—often sharing or selling data to third parties without meaningful consent.
Common attack flows
How it fits in a scam
Before
This is often where the scam begins.
Defense
How to defend against this
How to spot it
- Browser extensions (uBlock Origin or Privacy Badger) displaying high tracker counts on visited sites
- Same product ads appearing across unrelated websites after browsing or searching
- Use The Markup's Blacklight tool to scan any website for trackers
- Check EFF's Cover Your Tracks to test browser fingerprint uniqueness
- Browser settings showing dozens or hundreds of third-party cookies stored
- Targeted ads appearing shortly after discussing topics verbally near devices
Further reading
Electronic Frontier Foundation
Do Not Track and ad tracking overview
Electronic Frontier Foundation
How RTB surveillance is exploited by data brokers
Consumer Federation of America
How surveillance advertising tracking works
Federal Trade Commission
How websites and apps collect your information
Krebs on Security
Mobile ad data surveillance free-for-all
The Markup
Blacklight tool to scan websites for trackers
Malwarebytes
Browser Guard blocks ads and trackers