A federal judge has ruled that Google illegally monopolized digital advertising markets, potentially forcing the tech giant to sell parts of its advertising business in a decision that could reshape the digital marketing landscape.
Quick Takes
- U.S. District Judge Leonie Brinkema found Google guilty of illegally dominating two critical markets for online advertising technology: publisher ad servers and ad exchanges.
- The ruling paves the way for the Justice Department to seek a breakup of Google’s advertising business, potentially requiring the sale of Google Ad Manager.
- Google plans to appeal part of the decision while acknowledging it “won half of this case.”
- The court determined Google imposed anticompetitive practices that substantially harmed rivals, customers, and consumers.
- This ruling follows a separate case where Google was also found to have an illegal monopoly over the online search market.
Google’s Illegal Advertising Monopoly
U.S. District Judge Leonie Brinkema delivered a decisive blow to Google’s digital advertising empire on Thursday, ruling that the tech giant illegally monopolized two crucial markets in the online advertising ecosystem. The federal judge determined that Google maintained illegal monopoly power in both publisher ad servers and ad exchanges, while failing to prove monopoly in a third market for advertiser ad networks. The ruling represents a significant victory for the Justice Department in its ongoing efforts to rein in Big Tech’s market dominance and follows months of testimony and evidence presentation in a Virginia federal court.
The judge’s decision was unequivocal regarding Google’s behavior in the digital advertising marketplace. “Google further entrenched its monopoly power by imposing anticompetitive practices on its customers and eliminating desirable product features,” Judge Brinkema wrote in her ruling. She added that these practices “substantially harmed Google’s publisher customers, the competitive process, and, ultimately, consumers of information on the open web.” The impact was immediately felt by Alphabet, Google’s parent company, as shares fell 1.2% following the announcement of the ruling.
BOOM: Google loses ANOTHER antitrust suit, it's a monopolist of the software used by publishers to manage online ads, as well as the exchanges used to buy and sell online ads. pic.twitter.com/5bstcP50PN
— Matt Stoller (@matthewstoller) April 17, 2025
Potential Breakup and Remedies
The landmark ruling opens the door for antitrust prosecutors to pursue aggressive remedies, including a potential breakup of Google’s advertising technology business. Justice Department attorneys have suggested Google should be required to sell its Google Ad Manager suite, which includes both its publisher ad server and ad exchange. This approach aligns with previous considerations by Google to sell its ad exchange to satisfy European antitrust regulators. The court will now set a briefing schedule and hearing date to determine the appropriate remedies for the violations.
“This ruling is an unequivocal win for the American people that will help lower prices, increase competition, and lead to a better internet for everyone,” said Sacha Howarth, executive director of the Tech Oversight Project, following the decision.
The court could alternatively impose behavioral remedies to ensure fair competition without breaking up Google’s business entirely. During the trial, DOJ attorneys argued that Google abuses its market power by taking up to 35 cents per dollar spent on its ad platforms, a practice they claim harms both advertisers and publishers. Whatever the final remedy, legal experts believe the decision will significantly impact how digital advertising operates in the United States going forward.
Google’s Response and Future Legal Battles
Google has already announced plans to appeal part of the ruling while acknowledging partial defeat. “We won half of this case and we will appeal the other half,” said Lee-Anne Mulholland, Google’s vice president of legal. The company maintains that its publisher tools won in the marketplace on merit rather than through anticompetitive tactics. “Publishers have many options and they choose Google because our ad tech tools are simple, affordable and effective,” Mulholland added, disputing the court’s characterization of its business practices.
This ruling adds to Google’s mounting legal troubles. In a separate case in Washington, a judge will address the Justice Department’s request for Google to sell its Chrome browser and alter its dominance in online search. Throughout these legal battles, Google has consistently argued that antitrust cases focus on past practices while ignoring current competition from other tech giants like Amazon and Comcast, which have established growing advertising businesses.
Broader Implications for Big Tech
The ruling against Google represents one of the most significant antitrust victories against a major technology company in decades. It signals a potential shift in how regulators and courts view concentrated power in digital markets. Judge Brinkema’s decision to “determine the appropriate remedies” could establish precedents for future cases involving other technology giants. The case reflects growing bipartisan concern about the market power wielded by a small number of dominant technology companies that control essential digital infrastructure.
With multiple legal challenges still pending and increased scrutiny from regulators worldwide, Google faces an uncertain future for parts of its business model that have driven its tremendous growth and profitability. While the company will continue to fight these battles in court, the ruling already represents a watershed moment in the regulation of digital advertising markets and could ultimately reshape how advertisements are bought and sold across the internet.
