We refer to this product as the Amazon Swindle because it has Digital restrictions management (DRM) and other malicious functionalities.
Malware and nonfree software are two different issues. Malware means the program is designed to mistreat or harm users when it runs. The difference between free software and nonfree software is in whether the users have control of the program or vice versa. It's not directly a question of what the program does when it runs. However, in practice nonfree software is often malware, because the developer's awareness that the users would be powerless to fix any malicious functionalities tempts the developer to impose some.
The Amazon Kindle-Swindle has a back door that has been used to remotely erase books. One of the books erased was 1984, by George Orwell.
Amazon responded to criticism by saying it would delete books only following orders from the state. However, that policy didn't last. In 2012 it wiped a user's Kindle-Swindle and deleted her account, then offered her kafkaesque “explanations.”
The Kindle also has a universal back door.
Amazon downgraded the software in users' Swindles so that those already rooted would cease to function at all.
The Electronic Frontier Foundation has examined and found various kinds of surveillance in the Swindle and other e-readers.
The Amazon Kindle has DRM. That article is flawed in that it fails to treat DRM as an ethical question; it takes for granted that whatever Amazon might do to its users is legitimate. It refers to DRM as digital “rights” management, which is the spin term used to promote DRM. Nonetheless it serves as a reference for the facts.