According to a recent report, the US Federal Trade Commission (FTC) is expanding its antitrust investigation of Google to determine whether the online giant is illegally requiring licensees of its Android mobile OS to use its search services, shutting out competitors. The FTC first revealed its co-investigation of Google with several state attorneys general in June, but at the time it was assumed that these agencies would focus solely on Google's dominant web services.

The expansion of the probe was first reported by the Wall Street Journal. According to that publication, the FTC and several US states are now investigating whether Google prevents smartphone makers from bundling search and other services from Google's competitors. I alleged in a recent, related editorial that Google is essentially "dumping" its mobile OS in the market by making it free to quietly advance its own search services, which are bundled with Android and already dominate the PC-based web search and advertising markets.

Google publicly says that it has done nothing wrong and suggests that the sudden spate of antitrust investigation is spurred by jealous rivals, and not because it's breaking the law. "With success comes scrutiny," a Google spokesperson said. "We're happy to answer any questions they have about our business."

Part of the FTC investigation mirrors my previous complaint: FTC lawyers are now probing whether Google is maintaining its lead in web search by bundling its search service in Android. According to market analysts, Android is now installed on nearly half of all smartphones sold, and the percentage of smartphones sales controlled by Android is only growing.

Of course, Android abuses are only part of the FTC investigation. The agency is also trying to determine whether Google unfairly pushes its own services via Google search results and de-emphasizes competing services. And the FTC is investigating whether Google is collecting information published by rivals—such as Yelp and TripAdvisor restaurant and hotel reviews, and so on—and copying it to Google services so that search users will never visit those rival websites.