A federal judge ruled Monday that Google violated U.S. antitrust laws by building and maintaining a monopoly in online search and text advertising. Judge Amit Mehta’s highly anticipated decision, which marks a major blow to Google and its parent company, Alphabet Inc., comes three months after closing arguments in a landmark 10-week trial. It represents the first anti-monopoly decision against a tech behemoth in more than two decades. The government, which filed suit in 2020, argued that Google had boxed competitors out by paying top dollar to Apple and mobile carriers like Verizon to lock up search results and ads displayed at the top of those pages. Mehta agreed, writing in his 277-page decision: “Google is a monopolist, and it has acted as one to maintain its monopoly.” Shares of Alphabet fell by more than 4 percent on Monday, according to CNBC, which cautioned that there had been “a broad decline in stocks worldwide.”