He explained in his announcement:

VLC media player is free software licensed solely under the terms of the... GNU General Public License (a.k.a. GPL). Those terms are contradicted by the products usage rules of the AppStore through which Apple delivers applications to users of its mobile devices.

We've written before about the Usage Rules in the App Store's legal terms, and how they conflict with the GNU GPL and AGPL. That's because we went through a similar enforcement action against Apple when we learned that a port of GNU Go (which is copyrighted by the FSF) was being distributed through the App Store. Unfortunately, Apple chose to make the issue go away by simply removing the software from the App Store. Rémi expects that Apple will do the same for this VLC port. He says that if they do, "users of iOS-based devices [will] be deprived of VLC media player, as a consequence of the intransigently tight control Apple maintains over its mobile applications platform."

He's exactly right about the source of the problem. The GPL gives Apple permission to distribute this software through the App Store. All they would have to do is follow the license's conditions to help keep the software free. Instead, Apple has decided that they prefer to impose Digital Restrictions Management (DRM) and proprietary legal terms on all programs in the App Store, and they'd rather kick out GPLed software than change their own rules. Their obstinance prevents you from having this great software on Apple devices—not the GPL or the people enforcing it.

Apple continues to use more DRM in their products: they just announced that a Mac App Store will be coming soon to their laptops and desktops, and you can bet it will have the same draconian restrictions as today's App Store. Meanwhile, people enforcing the GPL like Rémi are fighting against DRM, so that everyone can be in full control of their own computers. We're thankful to him for taking a stand. If you want to show your support, too, it's easy: just steer clear of Apple's DRM-infested App Store.