[eschwartz]

As pwalker8 said. And a couple observations:

Originally Posted by SteveEisenberg

I would venture to say that a significant portion of those illegally downloading books don't know what a torrent is.

Besides for the fact that you pulled that conjecture out of thin air (maybe book readers are less technologically inclined than, say, movie watchers? Then how do they pirate books anyway? What makes you think books are somehow less likely to be uploaded in torrents than movies? If anything, movies are more likely to be streamed directly from online, vs. ebooks are downloaded before being read)...

...Do you have a point?

There is no illegality where law enforcement gets anywhere near 100 percent enforcement coverage.

In real life, I'm sure most antitrust violators do get away with it, so long as they price within a range rather than all the same. Suppose I was to tell you that antitrust enforcement is worthless, because all conspirators have to do is meet privately and avoid discussing sensitive subjects in emails, and to burn anything in writing. Would you buy that? Then why should I buy that only torrents matter?

You're missing the point. Trying to enforce hash comparison on sites that are already proudly against the law is not going to accomplish anything more than the ongoing legal actions and shock-troop raids. Copyright holders trying to change the laws to be more advantageous for themselves (or at least they think so) are targeting the access points that are currently in a state of legal deniability. ISPs. Search engines. Both have the theoretical power to do more than they currently do... assuming that that were a good thing on any side.
Are you even aware of the previous incarnation of this law? Stop Online Piracy Act (Wiki)

And of course it also targets small businesses, especially startups, that have no practical capability to to develop systems that cost tens of millions of dollars in order to check every file they host. Takedowns are however within their capacity -- and they tend to follow those.

This illustrates one of several subtle advantages book publishers have over the music industry when it comes to reducing piracy. I realize there are ways to make book files not byte compatible. But there also are thoughtless perpetrators -- who imagine they are being helpful to readers -- who will upload exactly what they downloaded. That can and should be reduced.

• If I convert a purchased EPUB to AZW3, and then for some godawful reason decided to post it online, I have defeated byte-compatibility. By accident.
• If I add the book to calibre, then save it, calibre will modify the metadata headers, to the same effect on byte-compatibility.
• When companies watermark their ebooks, like e.g. Pottermore does, the delivered-to-consumer file is not byte-compatible.
• DeDRM software does not even attempt to strip unique metadata headers -- and for good reason. I would venture to say those exist too, once again leaving deliverable-to-consumer files as non-byte-compatible.

That was a guess as to what is being done. I'm sure you could catch some perpetrators that way. I thought of it, so others smarter than me have as well. I'm also guessing that none of the law enforcement methods are what you call efficient.

To reiterate -- no you can't, and the reason no "others smarter than me have as well" thought of this is because they wouldn't even bother to think of an idea that is so fundamentally flawed. Rather than idle speculation, they are being paid to think of solutions, and they don't follow wild-goose trains-of-thought that serve only to generate internet "discussions".

And while other methods may not be efficient enough to End Piracy In Our Time, they generally produce meaningfully-useful results, rather than than a bridge to nowhere.