Just read this in the Facebook Terms of Use:

When you post User Content to the Site, you authorize and direct us to make such copies thereof as we deem necessary in order to facilitate the posting and storage of the User Content on the Site. 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 sublicense) 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. You may remove your User Content from the Site at any time. If you choose to remove your User Content, the license granted above will automatically expire, however you acknowledge that the Company may retain archived copies of your User Content.

Let me translate that into human readable English (although it is pretty readable as it is):

By uploading photos to your Facebook account, you automatically grant Facebook the right to copy, publicly display, and distribute your photos for any purpose, wherever they want. You may remove your photos from your account if you want, but Facebook still owns the copies you uploaded and can still do whatever they want with those copies.

I’ll think twice before I upload any photos or videos ever again.