When EU politicians call for the breakup of Google, it can sound like sour grapes, the anti-American backlash of an aging continent envious and fearful of the wealth and power of young U.S. tech giants.

But should any American scoff at Thursday's nonbinding vote in the European Parliament, when lawmakers urged regulators to get tough with the search engine Goliath, they should know that behind the EU anti-trust probe of Google stand not only Europeans but U.S. competitors.

Indeed, to many in Brussels it is Google's fellow Americans, such as Microsoft, Expedia and TripAdvisor, whose complaints and big money lobbying have driven a 4-year-old investigation by the European Commission into whether Google abuses its dominance of Internet searches to push favored websites.