nostr:npub1qny3tkh0acurzla8x3zy4nhrjz5zd8l9sy9jys09umwng00manysew95gx seems Signal got a major flaw. You can copy a session and read/write from the copied session without Signal adding another session. Also proven on Linux. 
Discussion
🚨🚨 MAC and LINUX Signal app got major security issue 🚨🚨
"The encryption key used to encrypt the local DB that contains all the secrets and chat history is stored in plain text in a location accessible by any app, process or script started by the Mac user."