They seem to be aware of this. Amazon Transparency, if successful, will banish fakes. In its essence it's about provable origin of each item, back to the owner of the brand.
Amazon created the problem, and now they're selling a service to fix the problem. That they created. Heckuva business model.
And charging vendors for it. You have to buy the codes (5 cents per, no volume discounts) and then pay one of their preferred printers up to 15 cents per Transparency sticker.