Scenario 1: Artist B buys a line image of a cat licenced on a stock image website by Artist A. (licence terms-free to distribute, modify but must credit original artist). Artist B colours it and then places it on a creative commons clipart website without crediting the original artist. (Image can be used free for commercial use except merchandising, no accreditation required). Person C uses Artist B's image from the clipart website without the knowledge of Artist A. Is Person C infringing on Person A's copyright by using B's image? Is Person B allowed to post their image on the clipart website?
Scenario 2 Artist B uses Artist A's clipart to make their own version of the animal. They place this on a creative commons stock site-(free for commercial, no attribution required). Artist C uses Artist B's version in their own work, publishes and later finds that Artist B based their work on A's clipart. Artist A cannot be located and the work is only visible on a couple of free for personal use clipart websites. The work seems to be an orphan work. It cannot be ascertained if Artist B has permission to make the derivative. What is the legal position of Artist C (assuming no fair use/fair dealings)?