[Jinto]

I think the problem is more like this...

If TiVo uses DRM stuff in combination with e.g. a Linux OS in their boxes, then GPLv3 would allow anyone to manipulate that code, even the DRM one, which uses then GPLv3 Linux interfaces and libraries and thus becomes GPLv3 itself. There would be no way to declare the changes illegal. Thus anyone could write hacks and distribute them. Now the distributors of DRM media would not want to rely on such a system, thus disabling play back support of their media for unhacked TiVo boxes (I doubt that works on hacked ones). However, TiVo cannot sell boxes that need to be illegaly (legal as in changes to the software are allowed, illegal, as in bypassing DRM is not allowed) hacked/cracked before one can use them (this is too obvious for jurisdiction that TiVo would put up with the fact that their boxes are obviously used to bypass DRM - or at least that would be their main purpose and TiVo knows it yet distributes... which is close to providing the means to bypass DRM directly).

Now DRM is only one example... military software would be another and there are more...

If we consider that GPLv3 would be not really working in many countries anyway, since the GPLv3 has lower priority then local laws (and if the law says manipulating DRM software may be legal but bypassing DRM is illegal then I suppose that counts more then GPLv3 which allows to have the means to do it, but the other law forbids to actually do it... some jurisdictions may even regard the mere existence of the tools to bypass DRM as illegal). Thus this would not have big effect anyway, but give the software that is published under the GPLv3 a negative almost pirate like image, which is not good for the distribution of the software in the industry. And lets face it, if the software has no place in the industry then there is less development on it. (just my impression)