How the tech titan plans to argue that it’s not a monopoly.

Google's quick to remind observers that it's not Microsoft, and Wagner points out that technology has blurred the boundaries of mediums like newspapers, television, and radio. And a second line of defense is to define the market as all online advertising, in which it holds only around a 30 percent revenue share.

But that begs the question "Why bother?": There's no law against trouncing your business competitors. Ever since Judge Learned Hand's landmark decision in U.S. v. Aluminum Co. of America 64 years ago, the court has recognized that under certain circumstances a company may come to dominate its field through "superior skill, foresight, and industry."

It's hard to see Google as anything other than a model example of such a company. After scarcely 10 years in business, it's revolutionized advertising, offered countless valuable tools available to the public for free, and made the Internet vastly more accessible. It has also done a great job promoting open-source and competition online. Even as Varney branded Google a monopoly last year, she praised it for its "spectacular" innovation and "terrific work."

Moreover, nobody's come up with a particularly good case that the company has been stifling other companies. One of the government's antitrust reviews looks into Google's book scanning settlement—a deal that was already approved by a court and was forced by publishers. Another investigates a mild overlap between Google's and Apple's boards of directors—a situation that could easily be fixed by a resignation, assuming any court thought it was a problem. A third has just become public, focusing on whether Google and other leading tech firms have been shying away from stealing one another's most talented employees. None of the concerns threatens Google's core business or suggests a dastardly plot. And the business-to-business search engine suit mentioned earlier—filed by sometimes Microsoft counsel Cadwalader, Wickersham & Taft—provides plenty of speculation about how Google could use its market position to harm nascent competitors, but little proof that it actually did.

"If [regulators] think we're kind of a giant, we hope at least they view us as a gentle giant," says Wagner.

Still, Google has reason to dread the perception of even benign dominance. Just ask Gary Reback, an attorney for Carr & Ferrell who played a big role in pinning monopoly status to Microsoft in the 1990s. Even if U.S. antitrust law allows for justly earned monopolies, it's rare that a high-profile company ever gets to enjoy that status in peace. Relentless scrutiny is almost built into the law. In the Alcoa decision, often cited as the cornerstone of the "good monopoly" rationale, Judge Hand first praised Alcoa's foresight and then slapped the company silly for sensible behavior like building production capacity in advance of demand.