If you commercially distribute binaries not accompanied with source code, the GPL says you must provide a written offer to distribute the source code later. When users non-commercially redistribute the binaries they received from you, they must pass along a copy of this written offer. This means that people who did not get the binaries directly from you can still receive copies of the source code, along with the written offer.
You sort of proved the GP's point. Only if you choose to use written offer must the offer be good for any third party. If, instead, one distributes binaries with source, there is no obligation to third parties as they should have received source from their distributor.
It does lead to hilarious results sometimes. I recall a ReadWriteWeb article that BREIFLY became the top search result for "facebook login" on google. The chaos was amazing.
The comment section is riddled with people asking how to get to facebook, or why did facebook change their login, asking help with logging in on this "new" login page. It was epic. The comments are still up if you want to read them
They had to put a notice near the top of the article explaining that it was not a facebook page. Eventually google fixed it. I guess the point is, that yes these people need to be considered when designing UIs.
Microsoft, however, is subject to the jurisdiction of the U.S. Federal Court system, and when a Magistrate Judge orders them to produce something, they are compelled to produce it. It doesn't really matter where the something is. Basically the court is saying the search warrant can be executed like a subpoena.
From the linked article:
A search warrant for email information, he said, is a "hybrid" order: obtained like a search warrant but executed like a subpoena for documents. Longstanding U.S. law holds that the recipient of a subpoena must provide the information sought, no matter where it is held, he said.