For security reasons you should never stay logged in, always log out when finished - When logging in to a web service, a cookie is planted in your browser. This cookie has a unique ID value that identifies you while you're using the web service, and, possibly, when you come back later. If that identifier was stolen or hi-jacked, the person possessing it could, possibly, use your account as if he or she was you. Logging out usually invalidates this identifier for both you and the adversary. If you do not log out and your credentials are hi-jacked could mean you cannot log back in requiring you to change your password if the hi-jacker did not do that or create a new account. Also never store your passwords in your browser those to can be hi-jacked or stolen. Use a password manager that has encryptionI usually stay logged in, but today I was logged out unprompted. I try to log back in but it kept getting knocked off. I was finally able to change my password after restarting my phone. Should I be concerned?