It only gives you that right if you are open with the software you distribute. The example is perfectly applicable to the question GP asked. It shows when you

It only gives you that right if you are open with the software you distribute. The example is perfectly applicable to the question GP asked. It shows when you create a derivative work you are beholden to the upstream copyright holder, even if as in the case of the Sony kid your work is 100% your own effort and only references the upstream work for color. AVM might have copyright on the work they did, but as a derivative work upstream copyrights more or less trump their copyright. By violating the viral share and share a like bit of the GPL they may have lost their right to distribute their work, because it is a derivative work.