How does one Stack Exchange site know that I'm logged in to the other?
15879
How does SO's new auto-login feature work?
72191
Switch Stack Overflow account from Google login to Stack Exchange login
52532
How to get logged-in user's full name in windows?
42044
How does reputation between the main site and its meta work on SE 2.0?
138491
Going to chat.stackexchange.com takes me to Area 51?
13235
How does a new user begin using Stack Overflow/Stack Exchange?
55093
How can I add a Stack Exchange login to my preexisting account?
80734
Getting notifications from other Stack Exchange websites
37403
How can I tell when I logged into Windows?
115608
Why not have one login to all stack subdomains?
157679
How to find the machine from which a user logged into current machine using ssh?
62468
How do I display logged-in username IF logged-in?
78378
Where in the world do Stack Overflow users say they are from?
36912
How can I verify users the first time they log in?
67843
Determine logged-in status of users
60830
How am I being logged in automatically even if I clear all my Chrome data from "the beginning of time"?
65040
Indicate if a new contributor is new to Stack Exchange, or new to the current Stack