On Android, Google Cloud Messaging (GCM) which is has been replaced by Google's Firebase Cloud Messaging (FCM). The problem with this enforced replacement: In FCM Google Firebase Analytics is activated by default and sends data to the Google-owned server app-measurement.com. It is possible to deactivate this tracking in the Android manifest file - but many app developers are obviously not aware of this tracking at all. In the past privacy-oriented apps like Riot.im and Conversations were affected but fixed that oversight as soon as the developers were notified. Even the well-known messenger Signal (if installed from the Play Store) contains those trackers - but they are explicitly deactivated. So how can Android users deal with that nefarious problem? Here are 3 solutions: 1. Block those trackers (and many more) with, e.g., Blokada or AdGuard Pro. 2. Consider installing Pi-hole on a Raspberry Pi and route all your network requests through Pi-hole via a VPN (OpenVPN or Wireguard). 3. Replace Andoid with LineageOS (without GApps) and use apps from F-Droid only.
