I know that sponsored themes have been of great debate on here, but this question is not regarding whether or not they are good, but about GPL Licenses.
My designer downloaded a theme that he liked from http://wpthemeDOTnet/blacksmoke-wordpress-theme-ready-for-download
Called Black Smoke. After downloading he noticed that the theme had an encrypted footer with spam and the WordPress Bookmarks code removed and Spam inserted.
In the footer it said it was based on FarFromFearless theme but did not give the a link to them. The designer went to the site and noticed that the code was identical as their Lemon Lime theme (except for the added Spam Code).
We put back the original WordPress Bookmarks and took out the spam in the footer plus added a link to FarFromFearless site.
Since it was an exact copy: same code, same image names (image color modified), same CSS (colors modified) we just linked back to FarFromFearless and not the site that is claiming credit for design. I mean even the header image is the exact same except the color was altered and the new designer's logo on top.
Is this a violation of the GPL and is the creator of BlackSmoke violating the GPL License? I think at least the BlackSmoke theme should have a link to FarFromFearless and not just text.