Wagner, who is Google’s “senior competition counsel,” faces the Sisyphean task of convincing the world that his employer is not unassailable. “Competition is a click away,” Wagner says. It’s part of a stump speech he has given in Silicon Valley, New York and Washington for the last few months to reporters, legal scholars, Congressional staff members, industry groups and anybody else who might influence public opinion about Google.

Google has begun this public-relations offensive because it is in the midst of a treacherous rite of passage for powerful technology companies — regulators are intensely scrutinising its every move, as they once did with AT&T, IBM, Intel and Microsoft. Some analysts say that government opposition, here or in Europe, could pose the biggest threat to Google’s continued success.

The Justice Department derailed an important partnership between Google and Yahoo in November because of concerns it would cement Google’s dominance and reduce competition. And Google now faces three new government antitrust investigations. The Justice Department is examining the hiring practices at Google and other technology companies, and it is investigating a class-action settlement between Google and groups representing authors and publishers.

None of the investigations take aim at Google’s core advertising business. And unlike other technology giants in years past, Google has not been accused of anticompetitive tactics. Eyes are rolling, especially in reaction to the idea that Google is a relatively small player in a giant market.