US-Google face off as ad tech antitrust trial comes to close

VIRGINIA, United States

Google and the United States government concluded closing arguments on Nov. 25 in a federal court case centered around allegations of the tech giant's dominance in online advertising.

The trial is one of two high-profile antitrust cases currently involving Google. While a Washington judge recently ruled that Google’s search engine constitutes an illegal monopoly, this latest case—brought forward by the U.S. Justice Department—focuses on Google’s ad technology used across the open web.

Central to the case are accusations that Google unfairly monopolizes digital advertising by requiring publishers to rely on its trio of ad software products. Plaintiffs, including publishers like News Corp and Gannett, argue that this dependency forces them into Google’s ecosystem without viable alternatives.

DOJ lawyer Aaron Teitelbaum characterized Google as "once, twice, three times a monopolist" during his closing arguments. Judge Leonie Brinkema, overseeing the case, is expected to deliver her judgment as early as next month, although appeals are likely to prolong the legal process.

The government claims that Google’s control over the online ad auction process allows it to charge higher prices to advertisers while delivering lower revenues to publishers. By leveraging its financial power to acquire competitors, the U.S. Justice Department asserts that Google has cornered the ad tech market, leaving businesses no choice but to use its tools.

Google, however, has dismissed the allegations as the government attempting to manipulate market dynamics by favoring certain companies. Google argues that advertising on websites is only a fraction of the broader ad tech market, which also includes search, social media platforms, and apps where it contends it does not hold dominance.

Google’s legal team, led by Karen Dunn, argued that the case relies on a narrow definition of the market, ignoring competition from companies such as Microsoft, Meta, and Amazon, which are rapidly growing their share of online advertising. Dunn warned that a loss could shift power to these rivals rather than solving broader concerns.

If Judge Brinkema rules against Google, a subsequent trial phase will be required to determine the specific actions the company must take to comply. The DOJ maintains that this case targets Google’s conduct in the website ad space and believes such changes are necessary to restore balance in the digital advertising market.