Ok. How about this:http://i.imgur.com/heXkHzU.png

It's a partial screenshot of the article in my browser. I intend to use it in a lecture as an example of the complications behind fair use. (irl I really do teach such a lecture). Who is it attributable to? The artist of the drawing, me, techcrunch or mediachain?

In short: I am suspicious of any service, and there have been a few, that claims to be able to identify the owner or creator of a work. It's a layering problem, with nearly every digital image being at some level the property of a great many people.

(fyi: if this was a law exam, the best answer is "me" in that I created the composition and am well-covered by fair use in my use of it here.)