HarthiTrust.org Harthi means elephant in Hindi. Elephants have long term memories. HarthiTrust has digital collection of 10 millions books, 2.7 millions are in public domain. Most of its books are digitized by Google Books project.
Starting from 2004, Google digitized books from libraries. The deal was when Google returned the books, it also returned the digitized copies. All these libraries created Harthi Trust as a shared digital library - HDL
The copyrighted books are available only by search while the pubic domain books are available for full text view. The supreme court considered the "search of all books" is very different than reading a book. Therefore, HathiTrust's copyrighted book search is a tranformative use, which is considered as "fair use". No copyright infringement.