The internet is abuzz with Facebook and privacy due to the beacon thing - but another less discussed topic is the ownership of content issue. Simply uploading content to Facebook grants them full rights, commercial and otherwise, including sublicensing - their TOS really puts it into perspective. This is directly from their TOS:
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, commercial, advertising, or otherwise, 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.
For photography this is pretty nasty - they could resell all the photography on Facebook, legally. Without your knowledge, permission, and without giving you any of the profit. Not directly a privacy issue, but it could be, if your private and personal pictures started showing up in magazines, ads, etc. They do go on to say if you remove content, the licence expires, but they retain the right to archive it. Something to be aware of. I wonder if content gathered on your behalf via beacon falls into those terms?
Update: The Government of Canada created a little video trying to raise awareness about the issue.