I&#x27;ve recommended Signal (then TextSecure) to a number of non-technically savvy friends as a trustworthy app that takes security seriously. Moxie is somewhat unique in this respect, among the sea of proprietary apps put out by larger shops. Upon seeing these &quot;X is on Signal&quot; messages, I had a number of people contacting me with concerns. At least the outward appearance is that Signal is somehow leaking contact data to their servers. Presumably it is also alerting people to the fact that &quot;Joe&quot; is a Signal user, despite no communication with that user having taken place.<p>I realize that phone numbers are probably hashed before being sent, with only local contact data being displayed, but it has people concerned nonetheless. It starts to err more towards convenience, ease of use, and network building above security.