@Linux @delta @feld "That you know of" doesn't apply when Signal reports the subpoenas they receive and their responses with the data they provide:
https://signal.org/bigbrother/
This is going in circles. No service is Fort Knox. You have to accept some level of risk whether that be the service itself going bad or some outside force prying sensitive information from the service.
Signal, as shown at the link I've now provided three times and has been totally ignored throughout this conversation, mitigates first and third-party risk by collecting as little data as possible so they don't have it to give.