To what extent is this extortion? I mean, they have admitted to only selling to a government. That means they find and exploit vulnerabilities in software created by a private corporation, disclose the existence of a vulnerability publicly, but don't allow the corporate body the means of fixing it. This news, if publicised, would harm Google's reputation and goodwill, perhaps non-negligibly, and cause users to switch products. Unless, of course, Google outbids a government. Pay up or suffer - would this be extortion?