From more than one source it seems that Apple holds iPhones for sale out the back for white people, or as they call them 'promoters'. So if you look like you might be sending the iPhone abroad, to regions where the wealthy people there can't walk into a store and buy an iPhone 4, you may struggle to pick one up from an Apple Store. That seems pretty racist to me.
Not that it's a fact obviously and I'm not saying it's true, it's just that it has been said more than once. Hmmm.