The pseudonymous Mordaxus says, Kindle Brouhaha Isn't About DRM:
The issue is caused not by DRM, but by cloud computing. The problem is that Amazon has a cloud service in which Kindle customers can keep their e-books on Amazon's shelf, and shuffle them around to any Kindle-enable device they have (like a Kindle proper, or an iPhone running the Kindle app). Customers can even delete a book from their Kindle and get it back from the cloud at a later date.
The event is that Amazon removed the book from the cloud, not that it had DRM in it. If you are concerned by this, you should be concerned by the cloud service. The cloud service enabled Amazon to respond to a legal challenge by removing customers' data from the cloud. They didn't need DRM to do it. In contrast, if iTunes store or the Sony e-book store had improperly sold a book, they wouldn't be able to revoke it because they don't have a cloud service as part of the store. (eMusic, incidentally, regularly adds and removes music from their store with the waxing and waning of desire to sell it.)
This is why we need to look at it for what it is, a failure in a business model and in the cloud service.
Well, yes, OK. But also no: Without the DRM part, the Kindle users would have been able to copy their e-books to local storage (or to read on other devices) and wouldn't be as vulnerable to this. Plus, Amazon didn't just delete off-site copies, it deleted all local copies (which doesn't logically require DRM, but is likely enabled by it). And Amazon even delted user annotations on the deleted works — including at least one student's homework.