http://wordpress.org/news/2009/07/themes-are-gpl-too/
"PHP in WordPress themes must be GPL, artwork and CSS may be but are not required."
Since they are not, GPL2 has nothing to say about the matter.
These requirements apply to the modified work as a whole. If identifiable sections of that work are not derived from the Program, and can be reasonably considered independent and separate works in themselves, then this License, and its terms, do not apply to those sections when you distribute them as separate works. But when you distribute the same sections as part of a whole which is a work based on the Program, the distribution of the whole must be on the terms of this License, whose permissions for other licensees extend to the entire whole, and thus to each and every part regardless of who wrote it.
This is sufficiently vague to cause some confusion. When distributing GPL-licensed works alongside non-GPL-licensed ones, I would probably err on the side of making your intentions as to what is considered part of the GPL distribution, and what is not, abundantly clear.
I am, of course, not a lawyer, etc. etc.
The mail quoted at http://wordpress.org/news/2009/07/themes-are-gpl-too/ classified the images and css as standalone works. They then concluded that the standalone works did not fall under GPL2. But the excerpt in the parent seems to state that these actually must be GPLv2:ed if bundled with the derivative work, no?
So my interpretation is that the disclaimer is in conflict with the licence, since the licence actually requires you to GPLv2 standalone work when bundling with derivative. (IANAL)
The point about linking is that the viral part of the GPL kicks in with regards to the distribution of executables ("the licensee must provide the recipients with a complete source code in one of the following methods, when distributing the program in object code"). If code is dynamically discovered at runtime, then this viral aspect does not apply.
This issue is old, regarded by Eben Moglen as a loophole, and I expected GPL3 to address it. I think it has not.
Search HN for: Thesis theme. This has been debated to death and you will get the correct answers there.
You seem to be lacking a very basic understanding of these kinds of sites:
1. Not every user on the site has read every post on the site.
2. There are new users who have not seen previous content.
There is not much you can do about reposts. People who haven't seen the content before will upvote it.
But now I see that stuff, it filled a lot of holes for me, thanks.
Also, if you did get a copy of a product and modified the code, you would not have to distribute that code if you did not distribute the product or make it available for public use in some way. In other words, modifying the code itself does not necessarily trigger an obligation to distribute the code.
Also, from this:
"You are allowed to sell copies of the modified program commercially, but only under the terms of the GNU GPL. Thus, for instance, you must make the source code available to the users of the program as described in the GPL, and they must be allowed to redistribute and modify it as described in the GPL. These requirements are the condition for including the GPL-covered code you received in a program of your own."(Emphasis added.)
That seems to imply to me that if you are not "a user", you are not entitled to the code. So what constitutes a user with a theme? If I buy the theme and you do not, it would seem that I am entitled tot the code, you are not but I am free to give it to you if I wish. Also if I put the theme on my blog and you read my blog, are you then a user and entitled? Or am I then making the theme public and everyone is entitled?
On that last paragraph, see also: http://www.gnu.org/licenses/gpl-faq.html#UnreleasedMods
And yes, I would think that if you make it publically available on a blog and I download it then you have distributed it to me and thus you have to comply with giving me the source as well. IANAL, obviously.
There is of course subtlety around whether the theme in question is actually GPLed, which I think has been adequately covered by others.
Edit: on second read you say "They mention they are licensing under the GPL." em just mentioning that in their FAQ is likely not legally binding either. Your best bet is to check out the source, and see if the source references any license. Alternatively, you can find out if it's a derivative of an existing GPL licensed theme (afaik, most themes are derivatives) in which case it'd inherit the GPL from there, and it doesn't matter what their FAQ says.
Edit2: Turns out I was mistaken about the details of inheriting the GPL, read the sub post.
Yes, because the only one who can litigate on a copyright violation is the original copyright holder. GPL is just a license like any other in that regard.