While I failed to note the web address, there is a lawsuit ongoing about http://www.flicker.com being given credit for a photo from the site being used in an ad campaign. The suit just wants the girl in the photo to be removed from the ad campaign, but it does bring up the big question:
Does posting a photo to Flicker give them any rights to the photo?
I honestly don't know, but since the cave shots on this DB use Flicker, it would be interesting to look into the fine print to know if the photographers are giving Flicker rights to use the photos without further permission.
Personally, I don't submit photos to any contests or such where use of the photo is given unrestricted to the recipient. Note that National Geographic, Smithsonian, The Washington Post all use this legalese to acquire large numbers of high-quality photos which they can then use without paying the photographer, whether the photo wins the contest or not.
If just putting a photo on Flicker allows them to use it, legally, without credit or payment to the photographer I think that a bum deal.
Hope someone knowledgeable can look into this, as cavers are putting a lot of photos on Flicker via this board and should know if they are giving up rights of payment for usage (or even photographic credit) when doing so.
Keith Christenson