Tennessee is interesting in that it at least tries to collect taxes, without being too dickish about it. They passed a law, this March I believe, that requires Amazon to send it's customers who have items shipped to Tennessee the amount of money spent on items sent to the State. Amazon doesn't send them a list, per se, of what was bought or how much money, but the state knows that it's customers do receive these emails.
Tennessee is also confusing in that there's two tax rates for Amazon items, one for digital purchases (yes, EVERY digital purchase is taxed in Tennessee) and one for any item bought on the internet or mail/phone order. Conveniently, you can pay online at the Tennessee government page! How kind of them! Luckily,I moved to Las Vegas so I have to spend time figuring out a whole new set of rules! Yay!
On topic, if I had to guess, believe they stopped due to customers returning, to Amazon, their scratched screen 3DS back before they fixed the screen issue (if it was fixed at all, I don't remember if that happened).
