Piracy didn't start with the internet. It started with people recording TV shows and movies off of their TVs, copying VHS movies that they rented from Blockbuster, copying CDs and cassette tapes, even recording songs off the radio!
And even when a person gets a hold of something legally, it doesn't necessarily mean that the people responsible for it will get a cut. A person can legally buy something used or borrow it from a friend. In fact, to this day, most of my reading is done from books that have seen at least a dozen hands. Whether that be books I get for a quarter in a yard sale, books I buy for a couple bucks at Edward McKay, books I check out at the library, or books that go through my mom's book circles. It was only purchased once, and yet it saw many hands legally.
And really, from personal experience, the people that download illegally would have never bought the book (or other media) anyway, new or used. Sometimes it is a matter of budget (a teenage or college age student on a low budget). Sometimes it is a matter of not knowing an author/artist well enough to want to pay full price for it. Simply, if a person downloads it illegally, it isn't stealing because it would have never been bought to begin with. It's not taking any money out of the copyright owner's hands.
However, these illegal downloads are not without their merits. There are many an artist that I discovered, before Napster got shut down, that I would have never found if not for illegal downloads. It allowed me to sample the music and discover something new without paying (and let's face it, the little snippets that iTunes gives us isn't exactly enough to go by). That's great, because word of mouth is the single most important form of marketing in the music/book industries. One satisfied listener/reader might point out the new find to a dozen (or now via Facebook etc, hundreds) of new potential listeners/readers. That one lost sale could results in hundreds or, via repeated postings from friends of friends and on and on, thousands of sales. It's free marketing. In fact, a major Scifi/Fantasy publisher has taken this idea and ran with it. Thus, the Baen Free Library. It is a library of, generally, the first book in a series. It encourages potential readers to download, free of charge, the first book in a series, get hooked, and want to read the rest of them, which, of course, they'll have to purchase. It's a brilliant idea, especially in a genre that frequently has its readers buying books new because many libraries don't carry them and most used book stores are not large enough to include them.
And to make matters worse, the book industry is killing itself with its handling of the ebook platform. Many of these formats are only recently starting to figure out that by restricting the transfer of books so severely, they are in fact crippling what has always been an invisible, but very effective means of marketing... borrowing. I buy a book, like it, let a friend read my copy and then they get hooked. It might pass into a half a dozen hands before it gets back to me and I sell it to a used book store. Because of this limitation, I for one, am less likely to buy ebooks because, at least to me, I'm just not getting that good of a deal out of it. They are too expensive for what you are getting. There's no real printing cost (I'm not actually getting a hardcopy book that they have to print), I can't lend it out, and I can't sell it to a used book store. So why are they frequently nearly the same cost as the paperbacks? It makes no sense. If the price was more reasonable, the industry would do far better, especially when we are talking about people potentially transferring their collections to a new format.
So quit being so touchy and remember that word of mouth is your best form of free advertising.