Signal has that too https://whispersystems.org/blog/disappearing-messages/ And using GCM is only a problem for people running a custom Android ROM without Google Play Services. They can use MicroG instead. For the vast majority of people who do have Google Play on their phone this is completely irrelevant. Using GCM doesn't make Signal less private.

> Google doesn't see any data via gcm, it's just a tickle. If you want push messages, you gotta use a push network.

https://twitter.com/whispersystems/status/695399112833761283

Those who want to use Signal without GCM can help out with code https://github.com/LibreSignal/LibreSignal/issues/43 or money to anyone who does the work https://www.bountysource.com/issues/35722527-create-proper-p...

> I've also seen first hand how difficult 3rd party clients can be on large networks with actual client logic, and unfortunately we simply don't have the resources to deal with that.

> I hope that everyone here who prioritizes federation above all else moves to federated products that support their goals, and I hope that those projects can demonstrate that I'm wrong about the inability to build competitive user experiences over the long term.

> If the only thing that the remaining people here want out of LibreSignal is a websocket-only solution and gmscore isn't an option for whatever reason, I would consider a clean, well written, and well tested PR for websocket-only support in Signal. I expect it to have high battery consumption and an unreliable user experience, but would be fine with it if it comes with a warning and only runs in the absence of play services. However, I also realize that still won't help people that are trying to build a Google-free experience on Google's platform, since we still don't have the things we need to be comfortable distributing software outside of Play.

https://github.com/LibreSignal/LibreSignal/issues/37#issueco...

Here's a great comment about Wire
https://www.reddit.com/r/privacy/comments/57s7qw/wire_messen...

> The thing is, Wire is developed by a for-profit company that has yet to discover a sustainable business model. They seem to be in a hurry to gain users, boasting about their own app's security and privacy before it has ever been independently audited.

> In December 2014, when they launched Wire, they claimed they could not read their users' messages. They were forced to retract their statement when a journalist asked about it https://motherboard.vice.com/read/wire-built-by-ex-skype-emp... , and didn't add end-to-end encryption until March 2016 http://www.reuters.com/article/us-dataprotection-messaging-w... . Contrary to popular belief, the protocol they now use is also not the Signal Protocol, but a custom protocol that Signal's developers have said they don't recommend https://twitter.com/whispersystems/status/774482849609031680 .

> Wire's privacy policy states that they log metadata: https://wire.com/legal/#privacy

> Using the Service to communicate by chat, our servers store your encrypted messages and other encrypted content and log other information such as the time and date of your conversations, and the other user or users with whom you are communicating. When using the Service to make or receive calls, our servers log and collect time and date of your calls, and the other user or users with whom you are communicating.

>Meanwhile, Signal's developers have said that "there are no "safe" jurisdictions anymore, only safe services" https://twitter.com/whispersystems/status/783318001349070849 . Concerning metadata, Signal's privacy policy states: https://whispersystems.org/signal/privacy/

> Certain information (e.g. a recipient's identifier, an encrypted message body, etc.) is transmitted to us solely for the purpose of placing calls or transmitting messages. Unless otherwise stated below, this information is only kept as long as necessary to place each call or transmit each message, and is not used for any other purpose.

> This was put to the test in the "first half of 2016", when Signal's developers received their first subpoena. According to the documents that were published by the ACLU and OWS https://whispersystems.org/bigbrother/eastern-virginia-grand... , the Signal servers only store the number you register with (which can be anonymous https://yawnbox.com/index.php/2015/03/14/create-an-anonymous... ), the time you registered and the last time you connected to the Signal server (the precision of which is reduced to the day).

Here's a great comment about Wire
https://www.reddit.com/r/privacy/comments/57s7qw/wire_messen...

> The thing is, Wire is developed by a for-profit company that has yet to discover a sustainable business model. They seem to be in a hurry to gain users, boasting about their own app's security and privacy before it has ever been independently audited.

> In December 2014, when they launched Wire, they claimed they could not read their users' messages. They were forced to retract their statement when a journalist asked about it https://motherboard.vice.com/read/wire-built-by-ex-skype-emp... , and didn't add end-to-end encryption until March 2016 http://www.reuters.com/article/us-dataprotection-messaging-w... . Contrary to popular belief, the protocol they now use is also not the Signal Protocol, but a custom protocol that Signal's developers have said they don't recommend https://twitter.com/whispersystems/status/774482849609031680 .

> Wire's privacy policy states that they log metadata: https://wire.com/legal/#privacy

> Using the Service to communicate by chat, our servers store your encrypted messages and other encrypted content and log other information such as the time and date of your conversations, and the other user or users with whom you are communicating. When using the Service to make or receive calls, our servers log and collect time and date of your calls, and the other user or users with whom you are communicating.

>Meanwhile, Signal's developers have said that "there are no "safe" jurisdictions anymore, only safe services" https://twitter.com/whispersystems/status/783318001349070849 . Concerning metadata, Signal's privacy policy states: https://whispersystems.org/signal/privacy/

> Certain information (e.g. a recipient's identifier, an encrypted message body, etc.) is transmitted to us solely for the purpose of placing calls or transmitting messages. Unless otherwise stated below, this information is only kept as long as necessary to place each call or transmit each message, and is not used for any other purpose.

> This was put to the test in the "first half of 2016", when Signal's developers received their first subpoena. According to the documents that were published by the ACLU and OWS https://whispersystems.org/bigbrother/eastern-virginia-grand... , the Signal servers only store the number you register with (which can be anonymous https://yawnbox.com/index.php/2015/03/14/create-an-anonymous... ), the time you registered and the last time you connected to the Signal server (the precision of which is reduced to the day).

And two comments from Hacker News
https://news.ycombinator.com/item?id=12149642
https://news.ycombinator.com/item?id=11726188