This would be a good idea if all it did was affect the text invisibly — by using patterns of non-breaking spaces, for example. But the text itself is holy. You can't go dicking with someone's writing. A good writer will run down to the printing press and have pages re-set just to prevent a sentence breaking ungracefully onto the next page, and that's just the importance of formatting. It's even worse to go messing with the words and punctuation themselves. That's the kind of idea you can tell was invented by an engineer who doesn't like to read.
This is ridiculous. I don't see it coming into massive effect, in any case - most authors I know and follow, myself included, would rather their stuff be stolen than be altered in this sort of way. I could perhaps see it being used in textbooks and non-fiction works, but even then, I don't think it's likely. Writing is an art, and every word choice is intentional. Screwing with wording and punctuation screws with the work and the author's intention itself.
All you need is one savvy folk to figure out a way to crack the algorithm used (I'm assuming its randomly generated) and then apply it to pirated versions as they are downloaded. While that's certainly more complicated than I could manage, its not like it hasn't been done before. Think of it as the next step in keygens. That being said, won't this just mean that it really just takes a decently clever hacker to grab the e-book from a totally innocent person and then just set it up pirated and damn the consequences? Would you hold the e-book holder responsible if you couldn't catch the hacker? What a dull idea that won't get off the ground.
For prosecution purposes I take it. I had the same idea ten years ago, but figured there's no way to know who actually "leaked" the text anyway. So this strikes me as entirely pointless, as with most forms of copyright enforcement.copies that end up on the Internet can be traced back to the people who bought and allegedly pirated them