Cory Doctorow attempts to illuminate Google on the subject:

I'm still disappointed that Google puts restrictive notices on their public domain works (these aren't licenses, just "polite notices") that tell what you're not allowed to do with these books. I know they're worried about their competitors getting ahold of those documents, but that's the deal with the public domain: it doesn't belong to you, period, it belongs to all of us. Just because you scan a public domain book, it doesn't confer the right to control it to you.

The good news here is that Google is not, as Doctorow previously believed, holding customers to exclusive deals in which Google and only Google can index their book collections. He points out that had such a standard been applied to web pages, we'd all be searching with Lycos and Google wouldn't exist.