The implications are huge. Who owns the books on your Kindle, you or Amazon or maybe someone you've never heard of? As we move more and more to a digital world, we become more and more vulnerable to questions like this. I realized this a couple of years ago when my iPod was erased because my computer was reset. I eventually got the iPod memory back, but only when an Apple tech took me outside the Apple store and told me how to retrieve it. We had to go outside since it wasn't an approved Apple fix.
The Kindle wiping only adds to the questions opened by our new world of hosting everything on the Internet. If I don't physically hold that data, who owns it? Amazon shows that it believes it has the right to go into our expensive reading devices and delete something we've paid for. Does that mean that if I buy Microsoft Office and it's hosted by an Internet site, I can lose the rights (or access) to it?
Paper and ink (and CDs and DVDs) may be expensive to produce compared to pure digital. But at least you own it, and can be sure it will appear. If I'm only reading my newspaper online, what happens if someone decides I shouldn't read certain stories. It happens now in China and Iran as well as lesser-known places. I suspect we are going to have more of these questions raised in the future.