If you're a Facebook user and you post a lot of personal information (text, images etc.), you might want to read Terms of use for Facebook, especially the paragraph "User Content" terms:
User Content Posted on the (Facebook) Site
You are solely responsible
for the photos, profiles (including your name, image, and likeness),
messages, notes, text, information, music, video, advertisements,
listings, and other content that you upload, publish or display
(hereinafter, "post") on or through the Service or the Site, or
transmit to or share with other users (collectively the "User
Content"). You may not post, transmit, or share User Content on the
Site or Service that you did not create or that you do not have
permission to post. You understand and agree that the Company may, but
is not obligated to, review the Site and may delete or remove (without
notice) any Site Content or User Content in its sole discretion, for
any reason or no reason, including User Content that in the sole
judgment of the Company violates this Agreement or the Facebook Code of Conduct,
or which might be offensive, illegal, or that might violate the rights,
harm, or threaten the safety of users or others. You are solely
responsible at your sole cost and expense for creating backup copies
and replacing any User Content you post or store on the Site or provide
to the Company.
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, 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. 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. Facebook does
not assert any ownership over your User Content; rather, as between us
and you, subject to the rights granted to us in these Terms, you retain
full ownership of all of your User Content and any intellectual
property rights or other proprietary rights associated with your User
Content.
Note the text I've marked bold+italic - this is the part where Facebook claims the right to use ANY material you uplode in ANY way or form the choose.
Facebook just informed the world that they now have more than 10.000.000.000 images in their database (actually more images than Flickr and Photobucket combined), so they have plenty of material to sell/use as they see fit. The above text is from the complete Terms of use.