I've always felt it strange how Amazon has concentrated its resource on penalizing their own customers by locking down the portability/sharability of books - thus preventing customers from their full rights under copyright (such as full right to loan or sell on a book). They'll even enforce that by removing the API keys to sites like Lendle.
Yet they totally leave the door open for scammers to upload content they don't own the copyright to and have no interest in really enforcing that side of the business.
It's the main reason I won't buy a Kindle, as much as the thought of owning a beautiful ebook device reader attracts me so much.