Google Has Established Illegal Digital Ad Monopolies, US Judge Rules

Alphabet’s (GOOGL) Google has illegally held monopolies in the online advertising industry, a U.S. District Court judge ruled Thursday.

Judge Leonie Brinkema in Alexandria, Va., found that Google violated antitrust laws by “willfully acquiring and maintaining monopoly power” in both the market for publishers selling ad space and the ad exchange market that connects buyers and sellers. The U.S. Department of Justice failed to prove that Google operated a monopoly in advertiser ad networks, Brinkema said. 

The court will set a briefing schedule to determine “remedies” for the antitrust violations, which the DOJ has argued should include a divestiture of Google Ad Manager, which houses both the tech giant’s publisher ad server and its ad exchange business. 

The DOJ also has pushed for Google to sell its Chrome browser after a federal judge ruled last year that the company also holds an illegal monopoly over the web search market. A trial to determine whether Google will have to sell Chrome, or simply make it easier for companies to use other search engines, is set to begin next Monday.

‘We Won Half of This Case and We Will Appeal the Other Half’

“We won half of this case and we will appeal the other half,” Google Vice President, Regulatory Affairs Lee-Anne Mulholland said. “The Court found that our advertiser tools and our acquisitions, such as DoubleClick, don’t harm competition. We disagree with the Court’s decision regarding our publisher tools. Publishers have many options and they choose Google because our ad tech tools are simple, affordable and effective.” 

Meanwhile, the U.K.’s Competition and Markets Authority in September accused Google of engaging in “anti-competitive” practices by effectively inflating advertiser bids made through its ad exchange.

Shares of Alphabet slipped 1% in recent trading Thursday. The stock is down 20% in 2025.