Onavo Protect Android app, which had over 10 million Android installations, contained code to prompt the user to install a CA (certificate authority) certificate issued by "Facebook Research" in the user trust store of the device. In Android 11, released in September 2020, Google had completely blocked the mechanism which the app used to prompt a user to install the cert and no application would trust any certificate in the user store by default. In other words, it appears other apps would have trusted certs in the user store from Android Marshmallow (Android 6) and below, but from Android 7, released in August 22, 2016, they would no longer be trusted at all by other applications, unless due to a security configuration in the app's manifest file.