If I’ve read this article correctly, and the author is correct, Facebook now has plug-ins on 100,000 sites and growing, that tell it if you wander by, if you are “logged in” to Facebook.
I just went to Facebook, which is set to come up on my Profile page, then I went to the account settings, which gave me the choice to Log Off. To me, that means you don’t log off automatically when you click away from Facebook.
Thus, Facebook has a record of your browsing history, I assume available to the highest bidder. Google knows where you’ve been; but, somehow that’s not as creepy. I don’t think I like this; but, do I shut Facebook down; or, do I log out every time I leave it?