what do you think?

Just something that I thought of; what do you think of people that upload pics that no one knows who originally posted/created it? I know that there are a few pictures here on DA that no one knows who the original creator was because it's been around the internet so much, if you look through google it's in many places. What do you think if someone uploads it? Do they have the right if no one can credit it to the original person? Or is it free game? 'Cause I found a pic that I have no clue who originally created it (trust me, I've looked long and hard) and was thinking of posting it to DA because it is (creepily) REALLY (almost completely, except for eye color on the guy) similar to a pairing that we draw/write lots of things about. Should I still post it even if I don't know who rightfully owns it, even if I say that I don't own it and am looking for the original to give credit?

What do you think?