You might assume that whenever you upload your photos to Facebook, you retain the copyright. They're your photos, so only you have the right to use and distribute them, right? Well not necessarily. In return for using the services of Facebook, the site reserves the right to distribute your images freely and even make money from them within certain limitations without your consent.
Facebook explicitly states in its lengthy Terms and Conditions that by uploading content of any kind - photos included - you're effectively giving-up control of your material:
By posting User Content to any part of the Site, you automatically grant, and you represent and warrant that you have the right to grant, to the Company an irrevocable, perpetual, non-exclusive, transferable, fully paid, worldwide license (with the right to sub-license) to use, copy, publicly perform, publicly display, reformat, translate, excerpt (in whole or in part) and distribute such User Content for any purpose on or in connection with the Site or the promotion thereof, to prepare derivative works of, or incorporate into other works, such User Content, and to grant and authorize sublicenses of the foregoing.
This means not only do Facebook own your photos, but they can also grant other companies the right to commercially exploit them. However, it should be highlighted that according to the Terms and Conditions set out above, they can only use images in conjunction with promoting the Facebook brand itself.
Perhaps the most concerning thing though is that these Terms and Conditions can change at any time without asking for users permission the next time they log in. Rather, Facebook expect users to keep an eye on their blog where any new changes are announced. However, in response to an outcry of almost 150,000 users over one particular a change to Terms and Conditions in 2009, Facebook setup their own page where they welcomed users to discuss it, suggesting they are now more sensitive to the issue.
Other than this, there two simple pro-active ways you can protect your image rights on Facebook:
1. Restrict your privacy settings.
Facebook have pledged to respect the wishes of those who do not want their images published openly for all to see. Whether this respect extends to commercial exploitation of their images isn't clear but tightening-up your privacy settings can't hurt. Elena has written a useful guide to adjusting them here.
Adding a watermark is a surefire way to ensure that no one other than yourself will want to profit from images you upload and virtually eliminates the temptation of companies like Facebook to use your images for their own means. A good tool for this is iWatermark available on both Mac and Windows which allows you to drag and drop images to add an instant watermark to photos.