What You Need to Know
- For the second time in less than a year, a U.S. federal court has held that Google engaged in unlawful monopolistic practices.
- Although the U.S. District Court for the Eastern District of Virginia’s recent decision in the Google Ad Tech case rejected some of the government’s claims, the U.S Department of Justice (DOJ) has described the decision as a “landmark victory.”
- The Trump Administration is expected to continue to pursue high profile monopolization cases against companies in the tech industry.
On April 17, 2025, U.S. District Judge Leonie Brinkema held that Google had violated both Sections 1 and 2 of the Sherman Act by unlawfully monopolizing the publisher ad server and ad exchange markets and engaging in anticompetitive conduct to maintain its dominance (the Google Ad Tech case). This decision follows the DOJ's earlier success in bringing a Section 2 monopolization claim against Google for its search practices (the Google Search case), which resulted in the DOJ's first courtroom victory in a contested Section 2 case against a major technology company since the landmark Microsoft case in the early 2000s.
Although Section 2 monopolization enforcement actions over the past two decades have been rare, the DOJ’s recent wins in both Google cases may strengthen the agency’s push toward reinvigorated monopolization enforcement more broadly, particularly against tech companies.
Google Ad Tech Decision
Less than nine months after a federal court found Google’s online search and advertising practices violated Section 2 in the Google Search case, in April a second federal court found that Google violated both Sections 1 and 2 of the Sherman Act by unlawfully monopolizing publisher ad server and ad exchange markets. In doing so, the court rejected Google’s argument that digital advertising should be viewed as a single two-sided market based on the Supreme Court’s 2017 decision in Ohio v. American Express Co. (Amex). Instead, the court found substantial evidence that these two markets have distinct characteristics and functionalities and thus should be analyzed independently.
The court determined that Google unlawfully maintained and entrenched its monopolies in both relevant markets by tying its publisher ad server (DoubleClick for Publishers, or DFP) to its ad exchange (AdX), effectively requiring publishers to use both services together and thus restricting competition in each separate market. The court also held that, over the course of a decade, Google engaged in impermissible exclusionary practices by adopting rules that restricted publishers' ability to route inventory to competing ad exchanges and by designing its systems to prioritize transactions through its own ad exchange. In her decision, Judge Brinkema emphasized that Verizon Communications Inc. v. Law Offices of Curtis v. Trinko (Trinko) does not provide blanket immunity and ultimately determined that the refusal to deal doctrine under Trinko did not apply, distinguishing Google’s conduct from the conduct alleged in Trinko.
While the DOJ prevailed on several key issues, Google prevailed in defending against certain claims. Perhaps most notably, the court rejected the DOJ’s proposed market definition for advertiser-side ad network services, concluding there was insufficient evidence to treat it as a distinct antitrust market. In addition, the court declined to find Google’s acquisitions of DoubleClick and Admeld anticompetitive, noting that both transactions had previously cleared regulatory review and finding they did not independently violate antitrust laws.
Although the Google Ad Tech decision was mixed, Attorney General Pam Bondi described the decision as “a landmark victory in the ongoing fight to stop Google from monopolizing the digital public square,” and warned that the DOJ “will continue taking bold legal action to protect the American people from encroachments on free speech and free markets by tech companies.” Assistant Attorney General Abigail Slater similarly cited the Google Ad Tech decision as confirmation that Google had used its dominant position to “censor and even deplatform American voices.”
Looking Ahead
For decades, Section 2 monopolization cases were few and far between, often eclipsed by merger challenges under Section 7 of the Clayton Act and cartel prosecutions under Section 1 of the Sherman Act. Although the FTC gradually increased its Section 2 activity over the past two decades, the DOJ remained largely dormant following the Microsoft case. That changed markedly under the first Trump Administration, which revived DOJ Section 2 investigations and filed the first of two lawsuits against Google.
Now, with back-to-back courtroom victories in both Google cases, the DOJ is positioned to double down on Section 2 enforcement, particularly against tech companies with significant market shares. This is consistent with public statements by DOJ leadership, including Slater, who in a recent speech at the University of Notre Dame emphasized the administration’s commitment to confronting concentrated market power. “When he nominated me,” she noted, “President Trump assailed the use of ‘market power to crack down on the rights of so many Americans.’” The DOJ has already invoked the recent Google Ad Tech ruling in support of its monopolization case against Apple, noting in court filings that “[t]he Google court squarely rejected Google’s ‘refusal to deal’ arguments for many reasons that also apply here.” Taken together, these developments signal a sustained—and increasingly confident—enforcement focus on Section 2.
With more monopolization cases still pending, additional rulings in those matters may further shape how Section 2 enforcement evolves. However, given the DOJ’s recent Section 2 successes against Google and the DOJ’s hostile posture towards “Big Tech,” large tech companies and those with significant market shares may be facing intensified scrutiny of business strategies that could be interpreted as potentially undertaken to reinforce or maintain their market power.
Key Takeaways
- Tech companies with high market shares be aware of greater potential for Section 2 scrutiny, particularly around practices that may be viewed as entrenching their positions.
- The DOJ’s success in both the Google Search and Google Ad Tech cases signals that, going forward, the Amex precedent may offer less protection for digital platforms, particularly when the government is able to credibly assert separate markets based on functionality, customer behavior, and competitive dynamics.
- The Google Ad Tech decision reflects growing judicial skepticism toward Trinko's narrow approach to monopolization liability, particularly in the context of digital platforms that are not highly regulated, and it may encourage future Section 2 cases that focus on strategic interoperability restrictions and self-preferencing.
- The DOJ’s statements following the publication of the Google Ad Tech decision suggest that the Trump Administration is likely to pursue Section 2 cases against tech companies it perceives as having been engaged in censorship of speech or political activity.
