By embedding tracking code into millions of websites, Meta’s Pixel and Yandex Metrica have been able to map Android users’ browsing habits with their persistent identities (that is to say, with the account holder logged in). This method bypasses privacy protections offered by Android’s permission controls and even browsers’ Incognito Mode, affecting all major Android browsers. The international research team has disclosed the issue to several browser vendors, who are actively working on mitigations to limit this type of abuse. For instance, Chrome’s mitigation is scheduled to go into effect very soon.

These tracking companies have been doing this bypass for a long time: since 2017 in the case of Yandex, and Meta since September 2024. The number of people affected by this abuse is high, given that Meta Pixel and Yandex Metrica are estimated to be installed on 5.8 million and 3 million sites, respectively. It is also worth noting that evidence of this tracking practice has been observed only on Android.