I know this tiresome argument comes up every time Signal is mentioned, but there's an elephant there that seems relevant.<p>An totalitarian state would not need to run a packet inspecting firewall to find out who is using Signal. They have this information already in the plaintext SMS Signal broadcasts in order to collect verified phone numbers of their users. It is most likely in their power to turn off cell service for these endpoints, or even locate them and let the security service round them up.<p>It's a great service in many ways, but if you are revolting an authoritarian state, it's something to be careful of. At the very least, please be mindful of this and take care of yourself.