Google won the part of the antitrust fight that actually mattered to its balance sheet. A federal judge in Virginia ruled that the company illegally monopolized two critical corners of the online advertising market, then declined to break anything up.
Judge Leonie M. Brinkema issued her liability ruling on April 17, 2025, finding that Google violated the Sherman Act by unlawfully tying its publisher ad server and its ad exchange together in ways that squeezed out competitors. The Department of Justice had wanted structural relief, specifically forcing Google to sell its Ad Exchange, known as AdX. The judge pointed toward narrower behavioral remedies instead.
What Google actually did wrong
The case, filed by the DOJ and a coalition of states in January 2023, centered on two products that most people have never heard of but that quietly govern a large portion of what advertising looks like on the open web.
Google’s DoubleClick for Publishers, now rebranded as Google Ad Manager, is the dominant tool that website publishers use to manage and sell their ad inventory. AdX is the auction marketplace where advertisers bid for that inventory. Judge Brinkema found that Google maintained monopolies in both markets by linking the two products in ways that made it nearly impossible for rivals to compete effectively in either.
The practice the court flagged is called self-preferencing, where a company that controls infrastructure also competes on that infrastructure and tilts the rules in its own favor.
Why there is no breakup coming
The DOJ’s original ask was a forced sale of AdX, the auction marketplace at the center of the monopoly finding. During closing arguments, practical objections to that remedy surfaced quickly. Concerns raised during the proceedings included the sheer complexity of unwinding a product so deeply integrated into Google’s broader ad infrastructure, with some estimates suggesting a divestiture process could stretch beyond 14 years.
Judge Brinkema signaled that structural remedies, meaning actual divestitures or corporate breakups, were unlikely to be the outcome. The court’s preference leans toward behavioral fixes: requirements around interoperability, meaning competitors could plug into Google’s infrastructure on fairer terms, and constraints on the self-preferencing practices the court found unlawful.
The remedies phase of the case will play out separately from the liability ruling. Closing arguments were heard in November 2025, and the final remedies order will determine exactly what Google must change and on what timeline.
What changes, and for whom
For the broader advertising industry, the liability finding alone carries weight even without a breakup. A federal court has now formally established that Google’s dominance in open-web display advertising was not simply the result of building better products. It involved conduct that violated antitrust law.
The ruling also lands in the broader context of accelerating antitrust scrutiny of dominant technology companies across the US and in Europe. Google is simultaneously navigating a separate antitrust ruling in the search monopoly case, where the remedies debate is even more contentious.