The first rumour was that Amazon had to retrieve the books after pressure from the rights-holder, which had apparently changed its mind about the e-vailability of these masterpieces of socialist theory versus practice. Amazon later denied this, explaining that the works uploaded by a publisher, reported to be MobileReference, which did not have the rights in the first place.
Customers have not been thrilled to discover that, when they purchase a book using Kindle, they do not necessarily own it for life. One wrote on Amazon.com's forum: "When I buy a book, I own it. Today i find that when I 'buy' a Kindle book, I am leasing it and it is subject to recall by the issuer". One particularly disgruntled customer is Justin Gawronski, who was reading 1984 on his Kindle for a summer assignment and lost all his notes and annotations when it simply vanished. "They didn't just take a book back, they stole my work", he is reported to have said.
Amazon is reputedly reconsidering its policy. Presumably it makes more sense to be on the customers' side. The easiest way to do this is to let them keep the illicit download and leave it to the copyright owners to take action against such parties as they can realistically sue.