Here is one sample book, have fun.
Google lawyers have a FAQ: http://books.google.com/googlebooks/perspectives/facts.html
Fiction: If a book is still under copyright, scanning it without permission is illegal.
Fact: This is probably the most common misconception about Google Books, and about copyright law in general. The "fair use" provisions of U.S. copyright law (USC 17 107) describe the conditions under which someone may copy a work without the copyright holder's permission, like recording a TV show to watch later or quoting from an article in a blog post. Fair use is designed to safeguard copying that doesn't harm people's incentive or ability to produce and sell creative work, including books.
We've carefully designed Google Books to make sure our use of books is fair and fully consistent with the law. Copyright law is aimed at protecting and enhancing the value of creative works in order to encourage more of them–in this case, to ensure that authors write and publishers publish. We believe that by creating new opportunities for readers to find and buy books, we can help authors and publishers sell more of them. You can read more about fair use here.
Given the obvious risk of being able to reconstitute the book samples into the whole the established publishing regime must have disapproved. Google engineers must have seen that coming and had some reasonable arguments to defend the position. To be a fly on the wall there...