I came across this handy blog post today, which is of especial importance to professional photographers, those who are selling their work, but is of general interest to everyone on Facebook, I think. There are new applications that allow you to order prints of the photographs you upload to your Facebook account through Walmart, Target, and Walgreens. This sounds like a good thing, yes? But depending on what your permissions are set to, it also allows your friends, and maybe even friends of friends, to make prints from your albums.
It's really simple to disallow this. All you have to do is click "block application" underneath the logo in the upper left hand corner of these applications' pages.
The Walmart Application
The Target Application
The Walgreens Application
How do you know if you've blocked these? Well, if you click on the link and it takes you to the facebook wall page, that the sign of success.