It is true that Amazon pulled some e-books off Kindles after customers had paid for them. The problem is that those books were 'stolen goods' to which Amazon never had sale rights in the first place. The fact that those pirated e-books were Orwell's 1984 and Animal Farm makes me think this was a deliberate hack set up to embarrass Amazon. And it seems to be working, as the company first took the action silently, then has failed to manage the publicity around the incident, starting with the initial New York Times piece.
Mind you, if it's a set-up, I fully endorse the hack. But it does smell like a trap to me.