Just to further make my point. You can find the same “assumption of ownership” (this being my personal term for it) of your content sections in other popular sites. Remember, I am NOT a lawyer.
Interestingly the Twitter TOS adds some markup that tried to give you a sense of how they interpret what the wording of the terms means to them. I did not see that elsewhere.
Facebook actually seems to currently have the most user friendly wording. I know at one time it was really bad, but typical to Facebook a public backlash was required to humiliate them into changing it. They seem to actually say the license to them ends if you successfully delete your content from their site.
“You grant the Company and its affiliates a perpetual, irrevocable, worldwide, non-exclusive, royalty-free right and license to use, reproduce, modify, adapt, publish, translate, create derivative works from, distribute, publicly perform and publicly display your User Content (in whole or in part) and/or to incorporate such your User Content in other works in any form, media, or technology now known or later developed.”
“By submitting, posting or displaying Content on or through the Services, you grant us a worldwide, non-exclusive, royalty-free license (with the right to sublicense) to use, copy, reproduce, process, adapt, modify, publish, transmit, display and distribute such Content in any and all media or distribution methods (now known or later developed).”
“For content that is covered by intellectual property rights, like photos and videos (“IP content”), you specifically give us the following permission, subject to yourprivacy and application settings: you grant us a non-exclusive, transferable, sub-licensable, royalty-free, worldwide license to use any IP content that you post on or in connection with Facebook (“IP License”). This IP License ends when you delete your IP content or your account unless your content has been shared with others, and they have not deleted it.”