About two weeks ago, the FSF announced that it has taken action against the Apple App Store over their distribution of GNU Go. This has apparently set off some people like lefty and triggered a length and wide debate.
I personally very much support the action the FSF has taken. Anyone involved in distribution of copyrighted material is required to do due diligence on checking that he actually has a license to do so. This is not really related to the GPL.
Yes, this means that I can take GPL enforcement action to a retail store that is selling/distributing infringing products, and I can make them provide a declaration to cease and desist from further infringements. Of course, that declaration would only be valid for this single retail store. This is why in our gpl-violations.org work, we always try to go after whatever entity is responsible for the majority or all of those infringements, rather than after a single store owner.
The reason for this is simple: In many cases, it is impossible for you as the rights holder to find out who sold the product to the retail store, and track the entire supply chain back to whoever caused the GPL violation in the first place. Also, some of those entities might reside in a different jurisdiction, so you go after the first element in the supply chain that is in your own jurisdiction, to minimize the legal risk for you as plaintiff and maximize the output in terms of your local market.
But the case with Apple is different. They are not a small retailer down the road, but the entity responsible for providing the infringing software to (almost?) all of its users. They are running that App store as a commercial company and earn money from running it (even if individual apps might be free of charge). Free Software and copyleft licenses like the GPL are a very real phenomenon in the software industry today, so they should better have thought about a proper solution, not just for GNU Go but for the tens of thousands of existing GPL licensed software projects which people might want to port or re-use in iPhone applications.
They are already doing all kinds of verification/checking/review of software for other reasons (things many people might call censoring), and as part of that process they could just as well determine the license of the software, and provide a source code download link from their store. What is the big deal? If they (or other similar app store / market / ... providers) had thought how to address the problem, there are easy and pragmatic solutions to solve them in the architecture of such a app store / marketplace system.
Also, the fact that the FSF is taking legal steps is not wrong. Even if some people might dispute whether they actually have a valid case or not (I believe they do): This is what legal cases are for: To create a clear legal situation for all participants in the dispute, and to set precedent for future similar cases. Even only from that point of view it is good that they're doing this case. At the end of it, the legal situation will be more clear, both for Apple as well as for people who want to distribute GPL licensed software through their store.