Majority of health sites send troves of data about your medical searches to third-party companies
Looking Up Symptoms Online? These Companies Are Tracking You — It's 2015—when we feel sick, fear disease, or have questions about our health, we turn first to the internet.
Context & Ripple Effects
Motherboard's finding lands weeks after the EFF documented HealthCare.gov sending personal data to dozens of tracking websites, extending the same concern from one government portal to the majority of consumer health sites. The mechanism is ordinary web analytics and advertising trackers attached to pages where users type symptoms and disease fears.
The pattern has proven durable rather than episodic: four years later UK health sites were found sharing sensitive user data with Google, Facebook, and data brokers, Kinsa turned smart-thermometer readings into an illness-data business sold to Clorox, and by 2025 investigators caught state-run health care exchanges leaking data to Google, LinkedIn, and Snap. This article is the early marker of a decade-long leak.
First-order effects
- Users searching symptoms on major health sites have their queries transmitted to third-party tracker companies at the moment of search, before any diagnosis or treatment exists.
Second-order effects
- Adtech firms and platforms receiving this data gain the ability to infer medical conditions and target or profile users on that basis, turning health anxiety into an addressable advertising signal — the model Kinsa later formalized by selling illness data to consumer brands like Clorox.
Third-order effects
- Because government exchanges, commercial publishers, and connected devices all repeat the behavior, enforcement eventually shifts from site-by-site fixes toward structural privacy rules governing health-adjacent data — the trajectory the 2025 state-exchange findings keep alive.
The trend: Sensitive health browsing keeps flowing into the adtech ecosystem regardless of who runs the site — startups, publishers, or states — making health-data leakage a structural feature of web tracking rather than a one-off scandal.