The killer quote in the New York Times story on privacy, “Do Not Track” browser technology and potential regulation comes from Interactive Advertising Bureau SVP and general counsel Mike Zaneis: “The reality is if you had 50-80 percent of consumers opting out it could have a really significant negative impact on the third-party ad model.” That’s quite possible: a similar number of consumers signed up for the FTC’s Do Not Call registry. And that negative impact could extend beyond ad networks, if first-party advertisers – i.e., publishers – get dragged in. Behavioral targeting is one of the key promises of Internet advertising. The industry better figure out how to deliver it without having it legislated out of existence or made impossible by consumer actions. Google is the whipping boy this week, but it was Facebook before. Just being “transparent” might not be enough, as consumers might opt out without realizing what they’re losing.