That’s the title of an article in the Library Journal:
But, due to the vagaries of U.S. copyright law, some scans’ status can be more of a mystery. If a work was published between 1923 and 1963, but the copyright holder didn’t renew the copyright after its first 28-year term, it, too, is public domain. Those works should legally be accessible via the HathiTrust as well, but determining a work’s copyright status requires research. That’s where the Copyright Review Project comes in.
The University of Michigan Library—which alone has deposited more than four million scans to the HathiTrust project—was awarded a $578,955 Institute of Museum and Library Services grant (match: $655,898) in 2008 for three-year project. Its aim: to go through HathiTrust scans of works published between 1923 and 1963 and determine their copyright status.
The project has since expanded to include staff from other institutions, including the University of Minnesota, Indiana University, and the University of Wisconsin-Madison—currently about 20 staffers in all.
According to Anne Karle-Zenith, the Copyright Review Project Librarian at University of Michigan, the project has checked the status of about 95,000 books so far; of those, more than 52,000—greater than half—have been found to be public domain. The project looks at the books most recently deposited into the HathiTrust database, and that’s a lot of books: there’s a backlog of about 175,000 books currently, Karle-Zenith said.
More info in the article, including some books which are, surprisingly, in the public domain.