I'm not even looking at the Facebook terms of use and will use what is standard practice and something of common sense if you think about it.
1) Whenever you upload anything to a website which has a good TOU (Terms of Use), the TOU will specifically state that you grant the website owner the right to publish and display the content and that you warrant and represent that you own the rights to the content and to give them the right to publish and display it on their site. For most large sites, they don't extend the rights too far beyond publish and display or there would probably be a major backlash. User your original impression, e.g. who would upload their picture if anyone could then download it and have a license to use your photo as stock clip art for a hemorrhoids cure ad?
2) With regard to download policies, unless there is a specific reason and the corresponding right in the TOU, you will have no ownership or license in anything you download. For example, if you have a "mobile phone theme" website like I used to manage, then the uploader represents that (i) the uploader has the right to upload the content, (ii) to grant permission to the website owner to store, publish and distribute the content to end users to use, and (iii) to give permission via a limited license to end users to download and use the content. That's an exception which is an obvious necessity.
3) "Linking" rights is a matter that is murky, to say the least, but in virtually all cases that which you make public on the Internet can be linked to the same way you can publish an address of a home. (And in the same way, links to download pirated content can be viewed in a similar light as publishing the location of your friend crack dealer's house so that others can obtain illegal substances.) Embedding is a whole other ball of wax but, in the context of social networks, that's an understandable right that may be included in a TOS to make it possible and isn't altogether objectionable provided the uploader/owner can control the content by making it public/private and thus shareable/nonshareable.
In short - unless you can find a specific grant of right and license to use content on the Internet, assume it's protected and owned by someone. It does not just fall into the "public domain" just because there might not be clear accreditation as to who owns it or that it may relate to you in some fashion.
Hope this helps.