Various forms of technology intended to control who could read books have failed.
All of them have failed, and largely, for the same reasons.
DRM doesn’t work because it is as easily broken as the medieval chains were broken—which is why so many medieval book collections were ravaged for their valuable covers and the contents between the covers casually disposed of, which is exactly what happened to The Book of Kells in 1006.
DRM doesn’t stop thieves. It just stops honest people from buying and reading DRM books.
On the other hand, giving away books without DRM encourages people to buy more books. It works. And while I absolutely don’t think giving away books for free is a tactic for everyone, it’s awfully interesting that Cory Doctorow and Baen’s books seem to be less frequently pirated not because they’re free (not all of either entity’s books are free) but because good reasonably priced DRMless content does seem to drive out cracked illegal content on the basis of ease of use, and production quality/readability.
Thieves are thieves; they’re not new. Talk to a librarian or to someone who works in a bookstore. Thieves will steal.
Technological anti-theft methods fail because the genuine paying customer is alienated, annoyed and frustrated and so doesn’t buy or read the protected book. We buy and read another book—it’s not like there’s a shortage of books readers want to read.
The remedy is to concentrate on appealing to the majority customer–the honest people who want to pay for their books–and making them available without DRM. People like me who love books will buy multiple copies of the same book—we did this before ebooks, and we do it now. We’re the real customer‚we actually read our books as well as pay for them.