What does that have to do with Signal&#x27;s dependency on a mobile number? Signal is <i>not</i> an option for everyone, while other tools that use a less myopic design don&#x27;t have that restriction.<p>If the goal is to fight passive surveillance, it&#x27;s a bad idea to <i>artificially</i> exclude minority groups. Cell phones may be popular, but they are <i>not</i> universal.