A potential addition that could be implemented to create more private chat rooms

I have the idea for the creation of password protected chats where every time you try to look into the chat to view messages or type, you must inter a set password implemented by server owners or managers. This addition could bring more privacy to chatrooms, for instance lets say your sharing an account with someone and or letting someone else use your device, if this future is implemented they wouldn't be able to read or share messages  exchanged between you and other members of your chat circle.