FARK.com just underwent a major site redesign, and lost among the clutter is their new legal policy. One would intuitively think that simply posting a photograph to the forums over at FARK.com would not mean that one is surrendering their copyright to FARK.com for all time, but it would appear that that is no longer the case:
Fark.com is the legal owner of all copyright interests of Fark.com content. Each and every submission to Fark.com carries with it an implied assignment of the entire copyright interest in the submission. In exchange for the content and publication of that submission on Fark.com, Fark.com grants back to the submitter a non-exclusive, non-transferable and royalty-free license to republish that submission in any and all forms.
Essentially, this means that posting any of your content to FARK, be it photograph, text, or whatever, immediately and forever transfers your copyright ownership to the owners of FARK.com. If, for example, you post a photo, they are free to sell rights to your photograph to others or to use it without permission in any way they deem fit, including advertising. The owners of FARK are "generous" enough to grant you back a license to use your own photo as you wish, but you are forever barred from selling licenses on the photo, as you (A) no longer own the copyright, (B) have only been granted a non-transferable license, and (C) FARK has generated a Royalty Free license, meaning that the image can never be Rights Managed again. The owners of FARK now own your image, not you.