There is a “backdoor” in Signal nobody cares about, only Google can use it.
This is not primarily about a specific problem. The problem is that you just can’t trust a messenger that is – even partially – non-free software. Signal is, WhatsApp is, Facebook Messenger is, Google Allo is. Deal with it!
You can of course also fix the Signal app. LibreSignal was a fork of Signal that does not use any Google services and thus does not suffer from the problems mentioned, but releases were halted following WhisperSystems request to do so.
Den Bericht gibt's hier.