This entire notion of respecting DRM to such an extent is absurd. If you buy a kindle book from Amazon, regardless of legal details, it's fairly "yours" and just as is the case with a physical book, you should have the right and inclination to strip off its DRM and then use it across devices as you please, even send a copy or two to friends. The right because you bought it, just like you'd have once bought a paper book, and the inclination because as we've seen with many cases of sealed digital content "ownership" platforms in the past, buyers have a funny way of suddenly losing everything they supposedly own. Stripping DRM removes both problems completely and, yes, it's usually very easy to do using perfectly legal software like Calibre, for example.