While the privacy and permissions surrounding your Facebook-shared photographs have always seemed a bit of a gray area, a new service is pushing the envelope further by helping users print any of their Facebook friends' images -- even on coffee mugs, mouse pads and iPhone cases -- and have them delivered to their doorstep.

Photos At My Door asks you to login with your Facebook account to access all your Facebook photos and those of your friends, which you can then order prints of, or choose to order any number of objects adorned with the photo. 

You knew you were sharing your vacation photos with 500 of your nearest and dearest Facebook friends when you uploaded the images to the social network, but you may not have anticipated those images making their way to a coffee mug without you knowing about it.