In 2016 there are different levels of logged in: L1 - I think I know who you are because you have a cookie or I remember your IP or browser fingerprint L2 - I d

In 2016 there are different levels of logged in: L1 - I think I know who you are because you have a cookie or I remember your IP or browser fingerprint L2 - I definitely know who you are because you logged in during this session and have a cookie L3 - I trust you enough to show you your user info over https since I just asked you to log in and you gave a password or verified you with facebook. Obviously some bigger names are experimenting and trust their tracking enough to do away with authentication for some things. Personally, I have an anonymous mode on one site. It is "I don't know who you are but I remember you." They can use the site and then convert to a real user with facebook, google, or email/password.