This is much more than your typical license violation -- AVM is suing Cybits because Cybits exercised their GPL rights. So this is a very important case to legitimize the GPL.
If AVM is trying to stop Cybits from reusing the code from AVM that was under GPL in their own stuff, fat chance at that lawsuit.
If AVM is trying to stop Cybits from running modified versions of the GPL code on AVM hardware, then it's not really illegal directly for Cybits to do, but AVM could enforce code signing DRM requirements in their hardware (like TIVO does) to prevent anyone with fiddling with it.
Really AVM could just give up warranty and support for customers that change their software to run Cybits, or if it really bothers them, put signing requirements in their firmware.
If AVM were to win this case, could the copyright holders of the Linux source withdraw their license to AVM? Could the license be wielded as a sword and not just a shield?
I'm not a lawyer, but you are asking for free legal advice, so you get what you pay for. :)
No. The GPL (v2 here, the kernel will very likely never go v3 because Linus does not want to re-licence his contributions) grants you an irrevocable licence as long as you do not fall out of compliance with the terms. If AVM wins the courts would be affirming that they have not breached the terms.
It would also be up to said copyright holder to not only challenge AVM in court, but figure out how to do it without invalidating the GPL if they win.
If you could get every single person that has ever made an accepted change to the Linux kernel to agree, sure. Otherwise, I'm not exactly sure how that would work out.
> "Ironically, by preventing others from enacting the rights granted by the GNU GPL, AVM itself is in violation of the license terms. Therefore they have no right to distribute the software" says Till Jaeger.
Is there any more to this than the quote above? The GPL is viral. Sure, you own the copyright to any changes you've made to GPL'd software, but you give up a lot of those rights the moment you distribute. Don't like it? Look for something BSD/MIT licensed to modify and distribute.
The GPL is viral, but you're misapplying the term here. The viral nature of the GPL deals with how your own code (linked with the GPL) must be licensed, not with how you redistribute GPL'd code.
It depends on the grand complexity that is derivative work. A while back some kid wrote an EverQuest FanFic that someone found objectionable. Sony was able to sue for copyright violation because it was a derivative work. So no you may not own the copyright to changes you make to GPL software(any software really, nothing GPL specific there), because the court may rule it a derivative work. Wikipedia has a few more interesting examples, see Pygmalion towards the bottom. http://en.wikipedia.org/wiki/Derivative_work
But the GPL gives you the right to make derivative works. I highly doubt Sony did the same with respect to EverQuest. So I'm not sure how applicable that example is.
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.
True... perhaps it would be better stated as the GPL gives you the right to distribute derivative works.
I always thought that fan fiction lived in a legal gray area that was tolerated by some and not others. So in my opinion, it's a bad example to use in this case. GPL is very explicit as to your rights and responsibilities.
It's not true that "you may not own the copyright to changes you make ... because the court may rule it a derivative work." You may not be able to distribute those changes without violating someone else's copyright, but that doesn't affect the fact that you own the copyright to your own work.
Consider what would happen in your FanFic case if Sony tried to incorporate the kid's changes into EverQuest. The kid could sue them for infringement.
more information on Harald Welte's blog: http://laforge.gnumonks.org/weblog/2011/06/20/#20110620-avm_...