Judge Rules Google Illegally Monopolized Ad Tech, Then Refuses to Force a Breakup

Google won the only part of this fight that actually cost money.

U.S. Judge Leonie Brinkema in Alexandria, Virginia, ruled Wednesday, September 2, 2026, that Google will not be forced to sell AdX, its online advertising exchange, according to Reuters. That comes after Brinkema herself found, in an April 17, 2025 liability ruling, that Google illegally monopolized two ad tech markets. She's letting the company keep the asset the Department of Justice most wanted gone.

What Google Actually Did Wrong

The case, filed by the DOJ and a coalition of states in January 2023, targeted two products most internet users never think about. DoubleClick for Publishers, now called Google Ad Manager, is the dominant tool publishers use to sell their ad space. AdX is the auction marketplace where advertisers actually bid for it.

Brinkema found Google illegally tied the two together, locking publishers who used its ad server into also using AdX, according to Reuters. That's a textbook self-preferencing problem: the company that runs the plumbing also competes on the plumbing, and rigs the pipes in its own favor. Brinkema said the conduct "substantially harmed Google's publisher customers, the competitive process, and, ultimately, consumers of information on the open web," per Reuters.

A federal judge found Google broke the Sherman Act. The legal question was settled in April 2025.

Why No Breakup

The remedy question is a different fight, and the DOJ lost it. Prosecutors wanted Google to divest AdX entirely. At a remedies trial last year, the DOJ argued Google "cannot be trusted" to run AdX fairly given its own record, according to Reuters.

Google's counter, also reported by Reuters, was that a forced sale would be technically brutal and drag customers through a long, messy transition. Crypto Briefing reported that estimates raised during proceedings suggested unwinding AdX from Google's ad infrastructure could take more than 14 years. Google also worked to distinguish the DOJ's demand from its own earlier offer to sell AdX to resolve a European Union antitrust probe, a 2024 proposal first reported by Reuters.

Brinkema sided with the practical objections. She accepted most of the parties' proposed behavioral remedies instead of a breakup, meaning rules on interoperability and limits on self-preferencing, rather than an actual sale.

A Fair Read of the DOJ's Argument

The DOJ's position deserves to be stated plainly: a company found guilty of illegally tying two monopoly products together, one that a judge said harmed publishers and consumers on the open web, is being asked only to change its behavior, not give up the asset it monopolized with. Critics of behavioral remedies argue they're notoriously hard to enforce, require ongoing court supervision, and let the violator keep the market position it built through illegal conduct. This applies whether the target is Google, Meta, or anyone else.

Google's side has real weight too. Forced divestitures of deeply integrated tech infrastructure are not clean surgical cuts. If unwinding AdX genuinely risks over a decade of instability for publishers and advertisers who depend on it working, a judge weighing costs against benefits has a legitimate basis to prefer narrower fixes. Neither side's claim is settled by anything in the ruling reported so far. The remedies order itself will determine how real the behavioral fixes end up being.

Part of a Pattern

This is the third straight defeat for federal antitrust enforcers trying to break up a Big Tech company, according to Reuters. A federal judge in Washington rejected the FTC's push to make Meta sell off Instagram and WhatsApp, saying the agency failed to prove Meta holds a monopoly in a social media landscape that's shifted since the case was filed in 2020. Separately, the judge in Google's search monopoly case rejected a DOJ bid to force Google to sell Chrome, citing rising competition from AI products like ChatGPT.

Ad Manager, the umbrella business that includes AdX, isn't a huge piece of Alphabet's overall revenue. Wedbush's analysis of court documents put it at 4.1% of Google's total revenue and 1.5% of operating profit back in 2020, according to Reuters. More recent figures were redacted from the court record, so nobody outside the case knows exactly how big AdX has grown since.

The actual remedies order will spell out precisely what interoperability rules and self-preferencing limits Google now has to follow, and on what timeline. Closing arguments on remedies were heard in November 2025. The detailed order determining Google's specific obligations has not yet been issued in full, and it's the document that will decide whether Wednesday's ruling means real change for publishers or just paperwork.