[dublinben]

You're conflating GCM and the wider Google Play Services that is installed on most Android devices. As someone who actually uses AOSP without Google, it weakens your argument when you conflate the two.

[Sir_Cmpwn]

GCM depends on Play Services, so I'm really not.

[dublinben]

GCM is merely one minor component. The existence of the microg project proves that you can implement one without the other.

[Sir_Cmpwn]

MicroG does not implement GCM.

[floatboth]

MicroG does implement the GCM client! I've been getting push notifications through that thing for several months.

[kuschku]

No, it implements one half of it.

Signal still has to be linked with a proprietary binary, which contains lots of tracking code.

[Sir_Cmpwn]

Through Google, yes, but you can't bring along your own push notification delivery service.

[tptacek]

Your argument has become circular, because the what Signal uses push notifications for isn't security-relevant: the messages are empty and used only as a wakeup.