The U.S. Department of Justice and dozens of states opened their antitrust case against Google in Washington on Tuesday, accusing the tech giant of illegally monopolizing the internet search and related ad markets. 

On the first day of one of the biggest antitrust trials in decades, U.S. District Judge Amit Mehta heard hours of competing arguments about whether Google has held an illegal choke hold over the market for internet searches and digital advertisements over the last 12 years. The government’s ambitious case poses a massive threat to a company whose name has literally become synonymous with internet searches.