There's an inverse relationship between the level of authority you posted with and the level of accuracy of your statements. Defensive patents are extremely commonplace in the industry, and Google has never used a patent non-defensively to date. That is to say, they've only ever counter-sued when sued. You think a few thousand dollars is a big deal to a company like Google? Hell, for Google it's just the cost of the filing fee. Google has their own in-house legal department. They pay their lawyers regardless of whether they sit on their ass twiddling their thumbs or if they're in court fighting over patents. That means, the opportunity cost of filing a patent is minimal--just whatever the filing fees themselves are ($750 I think?).