The
difference between books and music and computer programs, davidmcbeth
et al, is that the law and case law currently says that one (the book copying, depending on facts) is infringement and the others (with restrictions) are not. This may not seem like a BIG difference, but it is a difference that counts in the courts.
That is why the "book-scanning" suits recently and currently in the courts have been interesting to follow.
I suggest you look over the Authors Guild actions (Authors Guild v HathiTrust, and Authors Guild v Google), and the early Kinko's action (Basic Books v Kinko's), all of which deal with the scanning of books. Read over what defenses have been and are being used. Note also how
successful these defenses have been so far.
You may also wish to read the Computer Software Protection Act, for a look at archival copies and what exactly that means in terms of the copyright law. The intention of this Act and others that allow for an archival copy to be made is NOT so that a person can have two copies of a copyrighted work when only having purchased one. If a purchaser of a computer program, for example, makes an archival copy of the program, the purchaser must retain both the original and the archival copy. If he sells or gives away the original, he must include the archival copy as well or destroy the archival copy. There cannot be two owners at any one time of a work that has only been purchased once.
Both TKOne and mcbeth mentioned the RIAA decision. See also the Family Entertainment and Copyright Act, that addresses the copying of copyrighted works.
There are many many other cases that have addressed the copying of copyrighted works, and the copying of books in particular. The decisions made in each case that makes it to court, of course, depend on the specific facts presented. The copying of a work in the public domain is legal (unless the public domain work has been altered and the altered work copyrighted, such as the Ted Turner colorized films), the copying of portions of a copyrighted work for educational purposes can be found a fair use (although the right to copy for educational purposes has limits), and the copying of a book in its entirety can be infringement (see the lawsuits mentioned above).
Whether you scan your own personal copy of a book or not is, of course, your decision to make. As the copyright law stands right now, however, you would (depending on the book in question) be infringing on the right-holder's copyright and you could if caught (and depending on the facts) get sued for infringement.
I advise against the book-scanning (in general, although specifics may change the legality) because I tend to think on a legal forum such as this one it is wise to advise people AGAINST breaking the law, even if the risk of getting caught breaking the law may be slim.