Google faces a moment of truth in the coming weeks over a lengthy US probe into potential abuse of its Internet search dominance, amid regulatory woes on both sides of the Atlantic.
The Federal Trade Commission is widely reported to be nearing a decision on whether to pursue Google for monopoly abuses, at the same time European regulators are conducting a similar review.
At least one member of Congress is warning the FTC to be wary of meddling in Google's business, but some of Google's rivals are pressing hard for action.
Critics point out that Google controls some 70% of the Internet search market -- and the advertising that goes along with it -- and may exert even more power in the mobile sector by controlling the Android operating system used on two-thirds of smartphones.
"These are practices which drive up prices and drive down competition," said Ben Hammer, whose Fairsearch.org coalition includes the travel websites Expedia and Kayak, mobile phone maker Nokia, and Microsoft, a company which faced its own antitrust case over a decade ago.
Google is accused of "scraping" content from other services like travel and restaurant reviews while keeping consumers on its own sites.
It is also under fire for allegedly promoting its own services -- including travel, restaurant reviews and YouTube videos -- in its search results.
Another of Google critics' concerns is the way the company limits how advertisers can manage ads with Google and competitors.
"They remind me a lot of Microsoft in the 90s: massively arrogant, having the feeling they have the power to do anything they want," said Rob Enderle, a Silicon Valley consultant and analyst.
"Companies that get this way eventually run afoul of the government, sometimes catastrophically. They haven't been competing fairly for some time."
Google's problems are not limited to Washington.
Google has also made proposals to regulators in the EU anti-trust probe into whether the Internet search giant had abused its dominant market position, which officials called "a good basis for further talks."