I'm a developer too and I know it doesn't sound technically possible, but after FB's behavior it really wouldn't surprise me. Collecting copies of every SMS from Android phones via Messenger when it only advertised using Messenger to send/receive SMS alongside FB messages? Downright lies and abusive to privacy.

Most of us knew how poor Facebook's developer data policy was and no one cared until Cambridge Analytica. I'm just waiting for this voice scandal to happen in the next year or two.