Period tracker Stardust shares users’ health data with analytics firm, says Mozilla research

Mozilla security researcher Shoshana Wodinsky used a similar technique of analyzing the network traffic of several period trackers, including Stardust, to understand how the apps collected and shared data (if at all) with third parties. Wodinsky found that Stardust was the only app out of the six tested that shared the user’s sensitive health data with another company.

As quoted by BBC News, a Stardust spokesperson said that RudderStack is “contractually prohibited from selling or using it for its own purposes.” As U.S.-based companies, both Stardust and RudderStack can still receive demands for users’ information from law enforcement for users’ health information that’s stored on their servers.

Stardust founder Rachel Moranis did not respond to TechCrunch’s request for comment on Thursday, or questions about whether the company has received demands for its users’ data. A spokesperson acknowledged receipt of an email but did not provide comment.

Of the six apps tested by Wodinsky, Mozilla recommended Euki as “squeaky clean,” as the app was not seen to be sharing any data with third parties with its core features, and the user’s health data did not leave their device.