From the Stack Exchange Cookie Policy:
"If you use the Stack Overflow Network, both Stack Overflow and third parties will use cookies to track and monitor some of your activities on and off the Stack Overflow Network, and store and access some data about you, your browsing history, and your usage of the Stack Overflow Network."
What information is collected by SE about users when they are not on the Stack Exchange Site?
What information is collected by third parties about users when they are not on the Stack Exchange Site?
How is this information used, and how is it protected?