Last year Google signed a deal with the US Authors Guild and the Association of American Publishers under which it would pay $125 million for the right to scan millions of copyrighted books and make them available to the public. Authors could then register and receive income for books which were used or read by the public.
Google would earn a share in the profits generated by sales of books.
Concerns have been raised over Google's rights over orphan works. These are works that are still in copyright but whose authors are unknown or cannot be found. The DOJ's concern is reported to be centred on whether or not the deal gives Google monopoly-like powers over orphan works.
The deal stems from a class action lawsuit brought by the Authors Guild and the Association of American Publishers over the alleged copyright infringement involved in Google's book-scanning. The deal settled that suit.
Meanwhile, a US court overseeing that settlement has allowed authors and opponents more time to lodge objections to or opt out of the system.
The deadline for objections to the deal or for authors to opt out of it on behalf of their works was to be 5th May, but a New York court has extended that by four months. Authors and those running their estates had asked for more time to evaluate the system before deciding whether or not to opt out of or oppose it.
The deal allows Google to scan books by default under the 'fair use' provisions of US copyright law. It said in October when announcing the deal that commercially available books would not be displayed in the book search unless the author had opted in to the system.
Google said at the time that out of print books would automatically be displayed, but that rights-holders could demand that the book not be displayed.
Google will sell institutional subscriptions to the service to universities and other organisations, as well as making individual book sales to consumers. It will keep 37% of the revenue generated, it said. Up to 20% of works will be viewable for free, but a fee will need to be paid for whole books.
The Internet Archive also digitises books. Peter Brantley of the Archive told Reuters that the DOJ had talked to him about the Google deal.
"There are legitimate antitrust issues related to Google's ability to solely commercialise this content," Brantley told Reuters. "We would like the court to say 'this is fine theoretically, but these orphan books, they don't have anyone to speak for them, so let's take them out of the agreement'."