In a groundbreaking decision that could reshape the digital advertising industry, a U.S. judge has ruled that Google illegally monopolized key aspects of online ad technology. The ruling opens the door for the U.S. Department of Justice (DOJ) to demand that Google sell off parts of its advertising business to restore fair competition.
On Thursday, U.S. District Judge Leonie Brinkema concluded that Google, a subsidiary of Alphabet Inc., deliberately acquired and maintained monopoly power in two critical ad tech markets: publisher ad servers and ad exchanges. These technologies are central to how websites sell advertising space and how ads are bought and displayed across the internet.
This legal blow to Google comes just days before it faces another major antitrust trial—this time over its dominance in search.
What This Means for Google and the Web
Publisher ad servers help websites manage and sell their advertising inventory, while ad exchanges connect advertisers with those publishers. These tools are vital for news outlets and content creators, providing a significant portion of their revenue.
Judge Brinkema wrote that Google’s behavior not only stifled competition but also harmed publishers and ultimately hurt consumers who rely on free online content.
However, the court didn’t find Google guilty of monopolizing advertiser ad networks, marking a partial win for the tech giant.
Google has vowed to appeal the decision. “We won half of this case and will challenge the other half,” said Lee-Anne Mulholland, Google’s VP of regulatory affairs. “Our tools are effective, affordable, and publishers choose them because they work.”
Despite the partial win, Google’s shares dipped 1.4% following the announcement.
A Bigger Battle Ahead
The DOJ is now pushing for serious consequences—including the potential sale of Google Ad Manager, which includes both the ad server and exchange services. This comes on the heels of another ruling last year where a judge found Google guilty of breaking antitrust laws related to its search business.
Pamela Bondi, U.S. Attorney General, hailed the decision as “a landmark victory” in the fight against tech monopolies. “We’re committed to protecting free markets and preventing tech giants from choking competition,” she said.
Senator Amy Klobuchar also praised the outcome, calling it a win for consumers, content creators, and small businesses.
A Trend in Tech Regulation
Experts say this ruling signals a major shift in how aggressively U.S. courts are willing to challenge big tech. Michael Ashley Schulman, an investment officer at Running Point Capital, called it “a major inflection point” for the tech industry, suggesting that companies like Amazon, Meta, and Apple could face similar scrutiny.
Already, Meta and Amazon are battling their own antitrust cases, and Apple is under DOJ investigation for alleged monopoly behavior in the smartphone market.
Next week, Google heads to court again—this time over its alleged search monopoly, where the DOJ may push for more drastic measures, including breaking up its Chrome browser business.
As the pressure mounts, the message from U.S. regulators is clear: no tech company is too big to be held accountable.
