What is a phrase or word for 'not logged in' state?
Solution 1:
The process of confirming a user's credentials and logging them in is often known as 'authentication'. Therefore, a commonly accepted term for a user's state before logging in would be 'unauthenticated'. (http://www.oxforddictionaries.com/definition/english/unauthenticated)
This would apply equally to registered and unregistered users as well as users that have failed to provide the correct tokens - in any of these cases authentication has not been completed.
A distinction can be made between 'not logged in' and 'logged out', in that 'logged out' may imply that the system has a record of a previous session where the user was logged in.