Blue Shield of California Exposed the Data of 4.7 Million People to Google for targeted advertising

Blue Shield of California shared the protected health information of 4.7 million individuals with Google over a nearly three-year period, a data breach that impacts the majority of its nearly 6 million members, according to reporting from Bleeping Computer.

This isn’t the only large data breach to affect a healthcare organization the last year alone. Community Health Center records were hacked in October 2024, compromising more than a million individuals’ data, along with an attack on lab testing company Lab Services Cooperative, which affected records of 1.6 million Planned Parenthood patients. UnitedHealth Group suffered a breach in February 2024, resulting in the leak of more than 100 million people’s data.

What happened with Blue Shield of California?

According to an April 9 notice posted on Blue Shield of California’s website, the company allowed certain data, including protected health information, to be shared with Google Ads through Google Analytics, which may have allowed Google to serve targeted ads back to members. While not discovered until Feb. 11, 2025, the leak occurred for several years, from April 2021 to January 2024, when the connection between Google Analytics and Google Ads was severed on Blue Shield websites.

The following Blue Shield member information may have been compromised:

  • Insurance plan name, type, and group number
  • City and zip code
  • Gender
  • Family size
  • Blue Shield assigned identifiers for online accounts
  • Medical claim service date and provider
  • Patient name
  • Patient financial responsibility
  • “Find a Doctor” search criteria and results

According to the notice, no additional personal data—Social Security numbers, driver’s license numbers, and banking and credit card information—were disclosed. Blue Shield also states that no bad actor was involved, nor have they confirmed that the information has been used maliciously.

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Source: Blue Shield of California Exposed the Data of 4.7 Million People to Google | Lifehacker

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