Researchers have found that Meta and Yandex are exploiting legitimate internet protocols to de-anonymize Android users by embedding tracking codes in websites. This practice allows them to bypass security measures and link web browsing identifiers to persistent user identities in their mobile apps. Google is currently investigating this issue.

Meta has paused its mobile tracking technology on Android after researchers revealed that the company, along with Yandex, exploited localhost ports to link users' web browsing data to their identities, circumventing standard privacy protections. Following this disclosure, Meta's tracking code was largely removed to comply with Google Play policies amid discussions with Google regarding the issue.