@StarFleet CarlThe problem with withdrawing your books from Amazon is that it won't keep legitimate copies off Amazon. Amazon sells used copies of textbooks, and you can't withdraw those. Students can sell to whomever they want, including people who will resell on Amazon.
Many of the books featured in that NY Post piece are not textbooks, also.
It's a lousy problem all around. Amazon doesn't ever touch many of the products that it sells, especially in the used-book market, so they have no way to verify the product. Publishers have no way to verify it either.
The solution, such as it is, is to give the purchaser a 100% refund and charge back the book vendor (or simply never pay them in the first place unless there's a valid sale). If they're never getting any money, there's no motive to send out counterfeits. Admittedly, that still lets high-quality fakes survive, but that problem is endemic to any non-highly-curated marketplace (ebay, any used book store, etc).