text: If you read the indictment, you can figure out easily how they used SIGNAL. They got hold of a phone that had the messages saved on it! 1. No phone calls were intercepted on SIGNAL. 2. No person to person messages were intercepted. 3. All related evidence comes from group chats. This strongly indicates that a phone was physically looked at. 4. SIGNAL is encrypted end to end. Never stored on a server. No user information is stored, other than phone number.5. BUT, and it's a big BUT, if you store the messages on your phone, that's the vulnerability. If your phone is confiscated, and messages have not been deleted, you are vulnerable.