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Period tracker Stardust shares users’ health data with analytics firm, saysMozilla research
Mozilla's research reveals that the period tracking app Stardust shares sensitive health data with analytics firm RudderStack, contrary to its privacy claims. The data, including users’ birthdates and reproductive goals, can potentially be linked back to individuals, raising privacy concerns about health apps sharing data with third parties.
Key points
- Mozilla's research found Stardust shares users' data with RudderStack.
- Data shared includes sensitive health information tied to unique identifiers, not names.
- FTC warns that even anonymized data can be linked back to individuals.
- Stardust claimed end-to-end encryption but TechCrunch found these claims to be false.
- Sharing data with third parties carries risks like security breaches and legal demands for information.
- Of six apps tested, only Stardust shared sensitive user health data; Euki was recommended as secure.
Why it matters
- Concerns over privacy in health tracking apps are part of a broader trend in 2025 around data security.
- User data sharing has been a foundational issue following the rise of remote health services post-2020 pandemic.
- As laws regarding reproductive health evolve, the security of personal health data becomes critical to user trust.
The findings about Stardust highlight serious privacy issues in health tracking apps, emphasizing the necessity for users to be aware of data-sharing practices, especially as concerns around reproductive health data security continue to grow.