How to Copyright Your Picture on Facebookby Fraser Sherman
Any time you create a work of art, which includes taking a photograph, you become the copyright holder. You don't have to do anything because copyright is automatic and vested in you as soon as the work is finished. Posting the photo on Facebook -- or Twitter, Tumblr or Instagram, for that matter -- doesn't affect your copyright. However, you forfeit control over what Facebook can do with your photo.
Formally registering the copyright doesn't affect Facebook's license to use the photos. About the only thing you can do if you're concerned is delete the photos from the site. Under Facebook's current terms of service, deleting the photos ends the license you granted -- unless you shared the images with another Facebook user who doesn't delete them. If Facebook sub-licensed them to some other website, that sub-license remains in effect too. You'll have to contact the licensee and ask about taking the photos down.