Judge Rules Google Illegally Built Monopoly in Digital Ad Market

A federal judge has ruled that Google unlawfully built monopoly power in its digital advertising business, siding with the U.S. Department of Justice in a major antitrust case that could reshape how online ads are bought and sold — and challenge the economic foundations of many websites.

This decision, from Judge Leonie Brinkema in the U.S. District Court for the Eastern District of Virginia, marks the second significant antitrust win against Google in under a year and the third such ruling in recent months. Collectively, these outcomes suggest mounting legal pressure on the tech giant, with potential penalties that could force dramatic changes across its business. However, appeals are expected and could take years to resolve.

Thursday’s ruling focuses on the $31 billion segment of Google’s ad tech business that matches advertisers with web publishers — the technology that determines which ads appear on websites across the internet.

The Justice Department accused Google of using its dominant role in both buying and selling online ad space to stifle competition, arguing that Google unfairly tied its ad server for publishers with its ad exchange. Judge Brinkema agreed, writing that this allowed Google to “establish and protect its monopoly power” in both markets.

However, the court did not support all of the government’s claims. One part of the case — involving Google’s advertiser ad networks — was dismissed. In response, Google said it plans to appeal the parts it lost.

“We won half of this case and we will appeal the other half,” said Lee-Anne Mulholland, Google’s VP of Regulatory Affairs. She added that Google’s advertiser tools and past acquisitions, such as DoubleClick, were found not to harm competition.

Still, Judge Brinkema concluded that Google’s practices had hurt rivals’ ability to compete, harmed publishers, and ultimately reduced consumer choice and access to information on the open web.

If the ruling stands, it could lead to structural changes, such as Google being forced to divest parts of its ad tech business. However, legal experts say that a full breakup is less likely given the government didn’t win on all counts. Instead, Google might face restrictions on how it operates and prices its services.

“The broader the finding of illegality, the greater the justification for bold remedies,” said William Kovacic, a law professor at George Washington University. “In this case, the outcome might lean more toward limiting conduct than breaking up the company.”

Critics of Google and advocates for media and tech reform celebrated the decision. Sacha Haworth, Executive Director of the Tech Oversight Project, called it “an unequivocal win for the American people,” saying Google had long used its dominance to hurt media outlets and raise online costs for consumers.

Senator Elizabeth Warren also praised the outcome, calling it “a big win in the fight to break up Big Tech” and the result of years of advocacy against tech monopolies.

This ruling is part of a broader movement to rein in tech giants like Apple, Meta, Amazon, and Google’s parent company Alphabet. Just this week, Meta CEO Mark Zuckerberg testified in a separate antitrust trial about his company’s acquisitions of Instagram and WhatsApp.

According to Kovacic, Thursday’s decision may encourage global regulators to take tougher actions against major tech platforms. “This could give them the confidence to push ahead,” he said.