Google's second antitrust trial starts Monday. Here's what's at stake.

For the second time in a year, Google (GOOG, GOOGL) is going to trial against the US Justice Department to defend its lucrative businesses.

Starting Monday, prosecutors and lawyers for Google are scheduled to give opening arguments in federal district court in Alexandria, Va., in the case that claims Google illegally maintained its dominance in three markets within the ecosystem that automates online advertising.

The case, to be decided by US District Court Judge Leonie Brinkema, a Clinton appointee, was brought in January 2023 by the Biden administration’s Justice Department, along with 17 state attorneys general.

“The stakes for both sides are very high,” New York University Law School professor Eleanor Fox said.

The trial comes just a month after Google suffered a defeat in a high-stakes federal antitrust case brought by the DOJ during former President Donald Trump’s administration. In that case, US District of Columbia District Court Judge Amit Mehta ruled that Google illegally monopolized the general online search engine market and the market for search engine text advertising.