| Signal’s claim to fame here is that they were subpoenaed in 2016 and could only supply account creation and last connection times: > The American Civil Liberties Union announced Tuesday that Open Whisper Systems (OWS), the company behind popular encrypted messaging app Signal, was subpoenaed earlier this year by a federal grand jury in the Eastern District of Virginia to hand over a slew of information—"subscriber name, addresses, telephone numbers, email addresses, method of payment"—on two of its users. > ... “The only information responsive to the subpoena held by OWS is the time of account creation and the date of the last connection to Signal servers,” Kaufman continued, also pointing out that the company did in fact hand over this data. https://arstechnica.com/tech-policy/2016/10/fbi-demands-sign... |
Yes, it's not strong proof, but it should be taken into account when comparing the goals and motivations of organizations developing various other communicators.
The organization behind your communicator app could be in the business of gathering data about you and selling it in various forms (Facebook, Google), in the business of selling hardware and add-on software services (Apple), or in the non-business of trying to provide you with private communications.