My take on this is summed up much better by Cory Doctorow, and best written up in the foreword of his book “Makers”, which he published for free online.

There’s a dangerous group of anti-copyright activists out there who pose a clear and present danger to the future of authors and publishing. They have no respect for property or laws. What’s more, they’re powerful and organized, and have the ears of lawmakers and the press. I’m speaking, of course, of the legal departments at ebook publishers.

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Why am I doing this? Because my problem isn’t piracy, it’s obscurity (thanks, @timoreilly for this awesome aphorism). Because free ebooks sell print books. Because I copied my ass off when I was 17 and grew up to spend practically every discretionary cent I have on books when I became and adult. Because I can’t stop you from sharing it (zeroes and ones aren’t ever going to get harder to copy); and because readers have shared the books they loved forever; so I might as well enlist you to the cause.