The blog Eye on Miami posted yesterday an excellent post on shfiting baselines. They show a series of photos of Weeki Wachi Springs, Florida: alive in 1950 and more or less dead in 2006. Check out their blog post and a couple of the photos that were posted.
I think people differ greatly on this issue. For example, if it were completely unidentifiable as my own, I would have no problem with a picture of my naked ass being posted on the Internet. Others would be absolutely horrified by the prospect.