If I sell some device with an upgradable firmware (which contains GPLed materials), I can allow users to download upgrades from my site without putting them through hoops to prove that they own the hardware. Yet if they ask for the source code, then I can put them through the hoops: convince me that you're actually one of my users, then you can have it.
And it's not because users who don't have my hardware cannot use the firmware. In fact, users of hardware which is not mine could potentially be users of the firmware. If a competitor clones my hardware, so that the firmware runs on it, the users of that cloned hardware can benefit from the upgrades that I provide, because I don't validate that they are using the genuine hardware.
I don't have to provide the cloned firmware with free upgrades and all to the users of the competing hardware, and in fact, I am not offering those upgrades to the users of that hardware. It just so happens that they are able to help themselves to it because it accessible (for the sake of the utmost convenience to genuine users). That is not the same thing as it being distributed to the entire public.
Just because something is accessible to the public doesn't mean that it's being offered to the public. Distribution requires some kind of offer. An accidental leak is not distribution, for example.
And it's not because users who don't have my hardware cannot use the firmware. In fact, users of hardware which is not mine could potentially be users of the firmware. If a competitor clones my hardware, so that the firmware runs on it, the users of that cloned hardware can benefit from the upgrades that I provide, because I don't validate that they are using the genuine hardware.
I don't have to provide the cloned firmware with free upgrades and all to the users of the competing hardware, and in fact, I am not offering those upgrades to the users of that hardware. It just so happens that they are able to help themselves to it because it accessible (for the sake of the utmost convenience to genuine users). That is not the same thing as it being distributed to the entire public.
Just because something is accessible to the public doesn't mean that it's being offered to the public. Distribution requires some kind of offer. An accidental leak is not distribution, for example.