Looking on the GNU GPL website, there is no references of theft, however I think that might be because you cant steal something which is free.
Developers who write software can release it under the terms of the GNU GPL. When they do, it will be free software and stay free software, no matter who changes or distributes the program.
The GPL:
* the freedom to use the software for any purpose,
* the freedom to change the software to suit your needs,
* the freedom to share the software with your friends and neighbors, and
* the freedom to share the changes you make.
It dosnt protect software that you dont want anyone else to have.
So its up to you if you want to publicly show the style.. When you go onto your website, some of your images will be saved in the cache, so i have "downloaded" that file, that doesn't mean its illegal.
(This is based on what I understand from reading the site)
Sorry. Unactive due to personal life.