In what is likely the most significant tech trial of the modern internet era, the U.S. Department of Justice is arguing that Google has grown into an “illegal monopoly” for search and internet ad sales that ought to be broken up.

Probably the most consequential tech trial of the 21st Century got underway Tuesday morning in a U.S. District Court in Washington, D.C. The Department of Justice (and 38 U.S. states and territories) are suing one of the most powerful tech companies on earth Google, a.k.a. Alphabet, for allegedly strong-arming their way into a monopoly on our search engine use and the internet ad sales market,

Yes, Google is the first search engine you see, and the automatic default search engine, on most connected devices. But, as the Associated Press reports, the government argues Google orchestrated this illegally with billion-dollar backroom deals to grab a dominant 90% share of the search engine market, and monopolizing “ad tech” ad sales to run through them.

“Over the past 15 years, Google has engaged in a course of anticompetitive and exclusionary conduct that consisted of neutralizing or eliminating ad tech competitors through acquisitions; wielding its dominance across digital advertising markets to force more publishers and advertisers to use its products; and thwarting the ability to use competing products,” the Department of Justice said when it filed the suit in January. “In doing so, Google cemented its dominance in tools relied on by website publishers and online advertisers, as well as the digital advertising exchange that runs ad auctions."

The case was actually launched in 2020 by then-attorney general William Barr under the Trump administration. But Google, being Google, has an army of elite, high-powered lawyers ready to push back against the government’s case.

The New York Times has a rundown of the major players in this case. The federal judge is Obama appointee Amit P. Mehta. The government's case will be run by assistant attorney general for antitrust Jonathan Kanter, Google’s top lawyer is the company’s president of global affairs Kent Walker. Current Alphabet CEO Sundar Pichai is expected to testify.

A separate Times report details the opening arguments that started Tuesday, where the government argued that Google has been paying $10 billion a year to the likes of Samsung and Apple to make Google the default search engine on their mobile devices, and to browsers like Safari and Firefox to make Google the default on their search engines.

And another AP report adds that the Justice Department argues that Google deleted documents that showed they were doing this, indicating they knew full well it was an illegal practice.

Google counters that they’ve achieved dominance simply because people like their product better.

"People don't use Google because they have to — they use it because they want to," their attorney Walker said in a statement to NPR. "It's easy to switch your default search engine — we're long past the era of dial-up internet and CD-ROMs."

The trial is expected to last ten weeks (not in a row, there will be breaks), and is likely to wrap up in early 2024. There is no jury, so the final call is Judge Mehta’s to make. If Mehta rules against Google, the punishment would be decided in a separate trial, with a different judge. That judge could break Alphabet up into separate companies, or simply forbid exclusive deals with browsers and mobile device manufacturers, or just levy some huge fine.

If Google getting taken down sounds unlikely, recall that it happened to Microsoft in 2001. Kids, back in that day, the dominant search engine was something called Internet Explorer, and Microsoft forced it onto pretty much every PC on the market. Hardly anyone used a Mac back then! Apple looked like a dying brand at the time, but was just starting its historic turnaround. And rival upstarts like Apple — and Google ​​— feasted on the market share created by Microsoft’s loss in a federal antitrust case. So history may repeat itself here.

Related: Almost Every State Except California Is Coming After Google In Antitrust Action [SFist]

Image: PARIS, FRANCE - JUNE 14: The Google logo is displayed during the Viva Technology conference at Parc des Expositions Porte de Versailles on June 14, 2023 in Paris, France. Viva Technology, the biggest tech show in Europe but also in a unique digital format, for 4 days of reconnection and relaunch thanks to innovation. The event brings together startups, CEOs, investors, tech leaders and all of the digital transformation players who are shaping the future of the Internet. The annual technology conference, also known as VivaTech, was founded in 2016 by Publicis Groupe and Groupe Les Echos and is dedicated to promoting innovation and startups. (Photo by Chesnot/Getty Images)