Section 6 of the GPL does say: "You may not impose any further restrictions on the recipients' exercise of the rights granted herein." Of course, this clause, literally interpreted, is unreasonably broad; I assume the FSF won't give me the passwords to their web servers so that I can overwrite their web site with copies of GPL software the FSF distributes, despite the fact that the GPL gives me the right to make and distribute these copies, and the FSF is preventing me from doing so in a particular way. And it's also obvious that, if a GPL-licensed binary has been copied into a computer's instruction cache, and this copy may be executed and is provided to the user in this fashion, but cannot be copied back out to memory or registers from there, nobody is violating the license.
Apple may be able to argue that they can restrict the use of the contents of an iTunes account as a whole, and that if you want to put the binary on something else, you have to get it there via a different path; the FSF would probably have a good case that Apple, in order to comply with the GPL, needs to provide the binary in some way that allows it to be redistributed in order for them to be allowed to also provide it in a way that's not exportable.
I'm not actually sure what the FSF would want Apple's initial response to be, considering that that didn't intend to distribute GPL software and their site doesn't have support for actions necessary to comply with it. I assume that FileHippo would similarly take down a file that was just an executable built from GPL sources, lacking a mechanism for accompanying it with anything and therefore unable to comply with the notification requirements.