Project Gutenberg versus Google Books

I have only recently realized that when a person downloads an ebook from Amazon, for example, they do not own that electronic copy. They have a license to use it. So I was interested in an interview I read with Michael Hart who invented the e-book and founded Project Gutenberg, one of the world's largest online collections of free e-books. Hart discusses the difference between Project Gutenberg's approach - anyone who downloads one of their ebooks actually owns the copy and can manipulate it - versus downloading a Google e-book, which is only an electronic copy, does not then belong to you, and cannot be modified in any way. Gutenberg books are those whose copyrights have expired or whose authors have given permission to Gutenberg to make available. Still, this issue about whether one actually owns the electronic copy or not is getting a lot of attention lately as libraries are being forced to purchase only a license to distribute ebooks and not the actual right to the ebook itself. This directly impacts a library's ability to meet patron demands for free access to information.