When you upload your videos, photos or blog posts to websites, do you know who owns your content. Read what the “Terms of Service” document of the most popular websites has to say on this point:

YouTube: For clarity, you retain all of your ownership rights in your User Submissions. However, by submitting User Submissions to YouTube, you hereby grant YouTube a worldwide, non-exclusive, royalty-free, sublicenseable and transferable license to use, reproduce, distribute, prepare derivative works of, display, and perform the User Submissions in connection with the YouTube Website.

Facebook: 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.

Flickr: Yahoo! does not claim ownership of Content you submit or make available for inclusion on the Service. However, with respect to Content you submit or make available for inclusion on publicly accessible areas of the Service, you grant Yahoo! the following worldwide, royalty-free and non-exclusive license(s) - “the license to use, distribute, reproduce, modify, adapt, publicly perform and publicly display such Content on the Service solely for the purpose for which such Content was submitted or made available.”

WordPress: By submitting Content to Automattic for inclusion on your Website, you grant Automattic a world-wide, royalty-free, and non-exclusive license to reproduce, modify, adapt and publish the Content solely for the purpose of displaying, distributing and promoting your blog. If you delete Content, Automattic will use reasonable efforts to remove it from the Website, but you acknowledge that caching or references to the Content may not be made immediately unavailable.

Blogger: Google claims no ownership or control over any Content submitted, posted or displayed by you on or through Google services. You or a third party licensor, as appropriate, retain all patent, trademark and copyright to any Content you submit, post or display on or through Google services and you are responsible for protecting those rights, as appropriate. By submitting, posting or displaying Content on or through Google services which are intended to be available to the members of the public, you grant Google a worldwide, non-exclusive, royalty-free license to reproduce, publish and distribute such Content on Google services for the purpose of displaying and distributing Google services.