Google is facing its biggest legal challenge in a Washington court, as it fends off accusations from the US government that it acted unlawfully to build its overwhelming dominance of online search.
Over ten weeks of testimony involving more than 100 witnesses, Google will attempt to persuade a federal judge that the landmark case brought by the Department of Justice is without merit.
The trial is the biggest US antitrust case ever filed by the company since the same department took on Microsoft over the dominance of its Windows operating system more than two decades ago.
John Lopatka, from Penn State's School of Law, said in a statement.
The case centers on the government's claim that it illegally forged its domination of online search by entering into exclusive contracts with device makers, mobile operators and other companies that left rivals no chance to compete.
By paying billions of dollars annually to Apple, Samsung, or carriers like T-Mobile or AT&T, Google secured its search engine default status on smartphones and web browsers and allegedly guaranteed its success to the detriment of competitors.
The biggest victims in the case were rival search engines that haven't scratched out a meaningful market share against Google, like Microsoft's Bing and DuckDuckGo.
Google has dominated the search market in the US and globally, capturing 90 percent of the market, with mobile usage on iPhones and phones running on Google-owned Android.
The company contends its success is thanks to the unbeatable quality of its search engine, which has been judged a cut above the rest since its launch in 1998 by founders Sergei Brin and Larry Page.
''T use Google because they have to- they use it because they want to,'' said Kent Walker, Google's president of global affairs.
The trial will be decided by Judge Amit P. Mehta, whose decision will come months after the roughly three months of hearings.
The stakes for Google areénorme if Mehta upholds any or all of the US government's arguments.
Remedial action may require a breakup of Google's far flung business or a change in how it operates.
Company has faced a significant legal battle in Europe, fined more than 8.2 billion euro for various antitrust violations, although those decisions are being appealed.
What Mehta decides, the U.S. case will almost certainly be appealed by either side, potentially dragging the case on for years.
In 1998, Washington's lawsuit against Microsoft ended in a settlement in 2001 after an appeal reversed an order that the company be split up.
Google was launched during the Trump administration, and the suit went over in the transition to President Joe Biden.
Biden has also made a point of challenging tech giants, but with little to show for it.
In January, Biden's Department of Justice launched a separate case against Google involving its advertising business, and this could go to trial next year.
The company also faces legal action from US states accused of abusing monopolies in ad tech and blocking competition in its Google Play app store.
Google and the states said on Tuesday that they have reached an agreement in principle to settle the Google Play case.