Yesterday, the news broke that the deadline for authors to opt-out of the Google book settlement was extended to from May 5 to September 4, 2009.

Later in the day it became clear that the opposition to the settlement is building strength. The Justice Department has launched an inquiry into the antitrust implications of the settlement. From the New York Times:

The inquiry does not necessarily mean that the department will oppose the settlement, which is subject to a court review. But it suggests that some of the concerns raised by critics, who say the settlement would unfairly give Google an exclusive license to profit from millions of books, have resonated with the Justice Department.

More on the specifics of the inquiry from Mobylives:

The probe seems to be focussed on the fact that, as a Reuters wire story reports, the settlement “would allow Google — and only Google — to digitize so-called orphan works” and sell access to them. Orphan works are books that are out of print, but still in copyright.

“There are legitimate antitrust issues related to Google’s ability to solely commercialize this content,” commented Peter Brantley of the Internet Archive. IA also digitizes books, and Brantley “said his organization had ‘multiple conversations’ with the Justice Department about the Google plan,” according to Reuters.