In a speech to the Association of American Publishers today, Microsoft associate general counsel Thomas Rubin launched a harsh attack on his company's chief rival, Google. At the core of his criticism is the assertion that Google is no friend to copyright holders.

"Companies that create no content of their own, and make money solely on the back of other people's content, are raking in billions through advertising revenue and IPOs," said Rubin. "Google takes the position that everything may be freely copied unless the copyright owner notifies Google and tells it to stop."

Harsh words, but accurate to a degree. Google's book search project uses an opt-out model, requiring copyright owners to inform Google that they do not want their books indexed. In contrast, Microsoft is part of the Open Content Alliance, a book-indexing project also backed by Yahoo, HP, and the Internet Archive. Unlike Google Print, the OCA is only digitizing books that are currently in the public domain. Books still under copyright protection will only be scanned if the publisher opts in to the program.

Google's Book Search program has been a sore point with publishers. The search giant was sued by The Authors Guild in 2005, which accused Google of "massive copyright infringement." Google has dismissed The Authors Guild's claims that Google Book Search is a "plain and brazen violation of copyright law," saying that the project fully complies with copyright law and that it is consistent with the principles of Fair Use.

Given Rubin's audience, Microsoft's broadside on Google is no surprise. The Association of American Publishers has been critical of Google's efforts and is no doubt receptive to Rubin's arguments: "Google has chosen the wrong path for the longer term," says Rubin, "because it systematically violates copyright and deprives authors and publishers of an important avenue for monetizing their works."

Moving beyond Book Search, Rubin brings up Google's AdWords and AdSense programs. Last month, we reported on the discovery that some of Google's AdSense customers were aiding piracy web site by directing traffic to them and selling advertising for them. Noting that Google reportedly earned $800,000 in advertising revenues from four of those sites, Rubin says that the incidents "are not the actions of a company that has the interests of copyright owners as one of its priorities."

In contrast, Rubin paints Microsoft as a friend of copyright holders. "Microsoft and most other companies, by contrast, take the position that they should get the copyright owner's consent before they copy," Rubin explained. "The Copyright Act, in our view, supports this approach. It's hard to see any justification for exempting Google from its requirements."

Microsoft and Google have definitely chosen different paths when it comes to copyright. Google's approach could be described as "index first, ask later." In contrast, Microsoft has been very willing to accommodate the concerns of copyright holders—witness the efforts to which Microsoft has gone to appease rights-holders with its new Soapbox video site—but the company does so to the point that it limits the usability of their products or makes them less useful to its users (e.g., the Zune's crippled WiFi functionality). It's a great strategy if you're primarily interested in building strategic partnerships with major industry players, but consumers arguably prefer Google's approach.