I think some perspective needs to be considered here. If you are posting pics to a flickr account, blog hosting site or similar, and have made your details known (an email address in your profile, and a clear statement relating to all of your work under that account) it would be very hard for someone to claim that the work was orphaned, even if metadata were stripped. It is known that people use these sites to post to a particular account - I'm not sure how any person could claim it was impossible to contact the owner in that instance.
But, as I said, the devil will be in the SI details.