In 2009, purchased books disappeared from people’s Kindles. This was due not to a technical malfunction but to Amazon’s exercise of a built-in capability. The books hadn’t been properly licensed to Amazon, so Amazon withdrew them from the market. Retroactively. What made things really ironic and provided great headlines were that the books included George Orwell’s 1984.

Here I’m not addressing the moral or legal propriety of the action, but the implications for file preservation in the fact that it could and still can be done. I’ve heard that Amazon has renounced the policy of retroactive withdrawal, but the technical ability still exists. Amazon uses it to implement its money-back policy; you can “return” a book within a certain time period, and Amazon will refund your money and delete the book.

The underlying problem is Digital Rights Management, or DRM. This refers to any technology that impedes the making or use of unauthorized copies of a digital document. If you buy a book which is under DRM, you haven’t really bought it; you’ve leased it for an indeterminate period. If you want to move a Kindle book to a different computer or reader, you can’t just copy the file over; you have to re-download it. It’s been reported that Amazon may put an undocumented limitation on the number of times you can download a book, or perhaps (as mentioned in the comments) an undocumented limit on the number of registered devices it can be on. According to mobileread.com, Amazon says that “Most books come with a maximum of six licenses, but their are some books that may have less. The amount of licenses a book comes with is determined by the author or publisher who owns the right to the content.”

The long-term risks can be worse. There is no guarantee any business will be around next year, and no guarantee that it will continue to support its products. Amazon isn’t likely to vanish quickly, but someday the Kindle format will go the way of Kodachrome film. When that happens, all the DRM’ed books you’ve bought for it will be a digital pile of ashes.

A company can pull DRM just because it feels like it. In 2007, Major League Baseball dropped DRM support for game videos that people had “purchased.” No refund, just poof. Similarly, when Google dropped Google Video, the content which people thought they had bought was gone. Google issued refunds, but only after coming under public pressure. Major League Baseball also backed down, though problems remain. It’s likely that less-publicized instances with other vendors have left customers permanently stuck.

DRM is an attempt to solve a real problem, the unauthorized distribution of digital copies of works with no compensation to their creators. I have no objection to its use with rental or single-view distribution of materials. But any document under DRM that you “purchase” will, sooner or later, die. If a book was published only under DRM, it’s gone, unless someone has hacked out an unprotected copy of the content. Under the Digital Millennium Copyright Act, breaking DRM protection is usually illegal, even if it’s to make a personal backup copy of something you’ve paid for.

The books on my shelves will last a good long time if I take good care of them. So will e-books that I download, if they’re in a standard format and I take care to back them up and convert them to a newer format when needed. But books under DRM are under the curse of death.

Suggestions: Books and other documents under DRM are like beer. You can’t buy them; you can only rent them. Don’t “buy” any content under DRM unless you’re willing to consider it a throwaway copy.