Isnt it a bit more concerning that we can modify these peoples settings by clicking the links? (at least it appears we can) I have not checked but there may be a way to modify the url string to view anyones email (sample URL taken from that guys post below)

http://www.facebook.com/o.php?k=16531b&u=100001103986041... (warning- clicking this link will log you out of facebook with no prompt)

Or, perhaps a way to take the authentication hash + mid hash's from above to perform another function on someone elses account. (like changing the email, or changing privacy settings)