The points he raises are mostly ones we've discussed over the past few months - ownership questions, proprietary formatting, restrictive DRM and licensing, and so on. But I thought it was worth blogging about his first point,which is just forehead-slappingly obvious and yet somehow I missed it. E-books - at least as they are sold by major providers today - pose a major privacy risk that physical books do not.

As Stallman notes, you can walk into a store and anonymously buy a physical book, often just with cash. At most you might be required to show proof of age for some materials but no record is kept of what you show. Contrast that with e-book purchasing, which requires a logged-in identity that is linked to credit cards, bank accounts, and other hard-to-remove traces. These purchase records can then be subpoenaed or seized by authorities who might have an interest in what you've been reading - bought any books on agricultural fertilizer lately? Or maybe you live in a Middle Eastern country and your government suddenly cares that you've been buying e-books about how to build apps that connect to Twitter's API.

Even if the authorities don't seize these records, we've seen ample evidence that some organizations will break the law to get at private information so they can publish it and up their circulation numbers. If your reading list is anything like mine there's plenty on it that could be cherry-picked for tabloid headline fodder. I don't think such concerns are far-fetched or academic. The Comic Book Legal Defense Fund, for example, has ample case files of people whose reading habits have proven unpleasantly interesting to authorities.