Two years ago, Amazon.com removed George Orwell's 1984 and Animal Farm from Kindle readers, and refunded the purchase price. The reason was that the copyright owners hadn't authorized the Kindle. This means, of course, that Amazon.com and anyone with the proper equipment and security recognition, can alter what's on the Kindle. If we become dependent on electronic readers, we might yet be subject to Orwellian censorship and rewriting of contents.
The notion of Orwellian rewriting of works was idiotic for hard copies, but now with electronic readers from a central location, the notion is now unfortunately plausible.
It's possible that at some point I may purchase such a reader. If I'm so tempted, I should instead purchase a similar PC instead, and download their reader software.