A little off topic but can anyone tell me why when I go to a website and then hit back facebook.com shows up in the back history? My company blocked facebook s

A little off topic but can anyone tell me why when I go to a website and then hit back facebook.com shows up in the back history? My company blocked facebook so I can't go back at all and have to manully select the last page I was at. bothsidesofthetable.com does this for me. I"m using IE8.