This may well violate photographers’ copyright and usage licenses. There doesn’t seem to be an full opt-out option, but there are ways to block these different photo companies from having access to your images.
Plus, most photographers post low-resolution images to Facebook, which would mean people printing from these apps might have extremely low quality prints.
The Digital Wedding Forum has a great write-up in their blog, along with links to the known photo printing applications on Facebook. It only takes a few minutes to go to each link and block them from printing. So, jump on over to their article and click through the links.