Mary received a chat message from her "boss" saying that his user ID and password have expired and he is not able to login to company network to continue with his work. He requests Mary to provide him with her user name and password immediately so that he can login and continue with his work. If fail to do so, might result in losing a major project and she will be held accountable for the lost and lose her job. Mary does not want to lose her job. Explain which social engineering principle is this. List and justify what should Mary do?