“When you use Signal, your data is stored in encrypted form on your devices. The only information that is stored on the Signal servers for each account is the phone number you registered with, the date and time you joined the service, and the date you last logged on.”
If they are so concerned about the privacy and lives of whistleblowers they should implement usernames (and multiple accounts) instead of forcing people to give their cell phone numbers to others.
The use of cell phones in an app supposedly made for dissidents and whistleblowers is the stupidest decision I’ve ever seen.