Grindr, the gay hookup app, has been accused of passing on highly sensitive information to companies including users' HIV status and location data.
The data would be sufficient to identify users individually, security researchers have warned.
That's according to Antoine Pultier, a researcher from Norwegian non-profit organisation SINTEF. He found that users' HIV status was being sent to two other companies, along with their email addresses, phone ID, and GPS data.
With all this information, it would be possible for companies that received the data, Apptimize and Localytics, to identify specific users and work out if they were HIV positive or not.
SINTEF also noted that Grindr was passing on user data to advertising companies.
Furthermore, the data was shared in plain text, which would have made it easy for hackers to read if they got their hands on it.
Grindr's chief technology officer, Scott Chen, told BuzzFeed News that there was absolutely nothing to worry about. He asserted that no user data was sold on to third-parties and that Grindr pays other software companies to use their services.
"The limited information shared with these platforms is done under strict contractual terms that provide for the highest level of confidentiality, data security, and user privacy," he said.
But the problem here is two-fold.
First, Grindr users may not be explicitly aware that their data is being shared beyond the app, which, once in third-party hands could end up anywhere - as seen with Cambridge Analytica's use of Facebook data.
Second, because of this, even if good intentions are presumed, Grindr still has to rely on the third-parties keeping the data secure and private, but providing hackers with multiple targets for highly personal data.
Grindr has since said it will stop sharing the information. But the revelation opens up, once again, questions over the level of access mobile apps and other companies have to people's private data and what they end up doing with it.
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