Yesterday I pointed you at a free ebook on piracy. Because of that post, someone gave me a link to this ebook. From the summary:
It is common to argue that intellectual property in the form of copyright and patent is necessary for the innovation and creation of ideas and inventions such as machines, drugs, computer software, books, music, literature and movies. In fact intellectual property is a government grant of a costly and dangerous private monopoly over ideas. We show through theory and example that intellectual monopoly is not necessary for innovation and as a practical matter is damaging to growth, prosperity and liberty.
You can download it as a free PDF.