turbocharged - 10:51 am on Dec 23, 2013 (gmt 0)
In other words, anything that isn't explicitly protected by copyright is in the public domain.
Whether the work is copyrighted or public domain does not really apply to Google. One need look no further than the Google Books project to see how US law fails to protect authors. The US Judge ruled it was fair use for Google to scan entire books and display snippets of text to allow them to be searched for/found online.
The US Judge did rule that displaying snippets is "transoformative" and permitted under fair use guidelines. In other words, Google can pretty much do whatever they want with whatever text you create online and in print, providing they display snippets. The Adwords revenue Google earns from those searching through these copyrighted works is theirs to keep alone.
As I said previously, the only way to protect your content from Google is to block them from it. Granted, most of the information displayed online is rubbish, but those who do invest heavily into creating professionally written content have legitimate concerns as to how Google will monetize their work.