ReadWriteWeb, a popular technology website, has a page that ranks highly in Google’s search results for “Facebook login”.
Check out the comments on the page. They’re filled with complaints from confused Facebook users who think that this is the new Facebook login page.
Quite clearly many people do not use bookmarks, or simply type “facebook.com” in the address bar but instead they Google for what they’re after and click on the first result assuming it is correct.