On September 16, the Eastern District of Virginia unsealed Judge Leonie Brinkema's 106-page remedies opinion in United States v. Google, the Justice Department's ad tech monopolization case. Google will not be forced to sell its ad exchange or open-source its auction logic. The court found structural relief "neither realistic nor needed" and instead adopted detailed behavioral remedies aimed at the conduct it found unlawful.

This is the second time in a year a federal judge has rejected the government's case for breaking up Google. Read with Judge Amit Mehta's Search ruling, the decision sets a clear marker: courts will aggressively remedy proven violations, but will not order the radical step of divestitures when the liability record does not support it.

Background

In April 2025, Judge Brinkema held that Google violated Sections 1 and 2 of the Sherman Act. Google monopolized two worldwide markets for open-web display advertising: publisher ad servers, where its product is DFP, and ad exchanges, where its product is AdX. Both products came to Google through acquisition.

Google’s 2008 purchase of DoubleClick brought it the ad server that became DFP, it launched the exchange that became AdX the following year, and it acquired the yield optimizer Admeld in 2011. In 2018, Google combined the two under a single publisher-facing platform, Google Ad Manager, which the court found further intertwined them. The core violation was a tie between the two products.

The court rejected the government's advertiser ad network claim and did not find the DoubleClick and Admeld acquisitions anticompetitive on their own. AdX and DFP remain a single Google product line, but Google can no longer condition access to one on the use of the other.

By the close of the remedies trial, both sides had proposed substantially overlapping behavioral remedies. The government also wanted three structural remedies: divestiture of AdX, open-sourcing of DFP's final auction logic, and a contingent divestiture of whatever remained of DFP.

What the Court Ordered

The order breaks the tie and eliminates the tools Google used to enforce it. Google may not enforce any policy or contract term that ties DFP to AdX, and it may not recreate that tie through other means. First Look, Last Look, and Unified Pricing Rules are prohibited for all indirect transactions, and publishers regain the ability to set different price floors on different exchanges. According to the plaintiffs' own expert, eliminating Unified Pricing Rules alone would cut AdX's 20 percent take rate to roughly 16.6 percent, in line with rivals.

Google must build integrations that allow Prebid, the open-source header bidding platform, to solicit real-time AdX bids for all indirect open-web display inventory. DFP publishers must be able to route both indirect and programmatic direct demand through Prebid, and rival publisher ad servers must receive AdX bids on the same terms DFP does.

Publishers will also be able to export their DFP data to competing ad servers and obtain AdX bid data, including losing bids. Rather than requiring Google to publish source code, the court required technical documentation explaining how DFP selects ads, together with a data file for each ad served that shows the candidate prices, any adjustments applied, and the reason the winning ad was chosen.

A Monitor with access to Google's documents, employees, and source code will oversee compliance, supported by a Technical Committee and an Internal Compliance Officer. The final judgment will run for six years, apply worldwide, and take effect 60 days after entry.

What the Court Rejected

The court's rejection of divestiture relies on the D.C. Circuit's decision in Microsoft, where structural relief requires a "significant causal connection" between the unlawful conduct and the monopoly, which is a more demanding showing than liability requires. The plaintiffs did not meet it. Lawful factors, including the advertiser demand AdWords draws from Google Search, acquisitions regulators had cleared, and sustained investment, contributed substantially to Google's position. The court also noted that divestiture would be unprecedented where the violation is a tie among integrated technology products.

The court was direct about the government's underlying rationale, which it concluded came down to distrust of Google and "an unrealistic desire for certainty." Neither can justify a breakup. Courts presume compliance with their orders, and Google remains exposed to contempt sanctions and a growing number of private lawsuits, which would be “swords of Damocles” to keep it in check.

The plaintiffs never identified a viable buyer for AdX, which is deeply integrated with Google infrastructure spanning more than 100 million lines of code. Comparable-sized migrations have taken five to eight years to complete. Behavioral remedies, by contrast, can be fully implemented within 15 months.

The proposal to open-source DFP's auction logic failed for a more basic reason: the plaintiffs never argued, and the court never found, that the auction logic was part of the violation. It was also impractical: a single DFP function depends on a daily computation running ten hours across 4,000 machines, and operating open-source auction code would burden smaller publishers. The contingent DFP divestiture failed for similar reasons and risked raising costs for a product more than 90 percent of DFP's publisher customers use for free.

The court also rejected the plaintiffs' demand that Google pay half of its AdX and DFP net revenue into an escrow fund, finding no connection to its liability findings. It declined to extend data sharing to all ad formats or to impose remedies on Google's DV360 buying tool, struck anti-circumvention and anti-retaliation provisions as too vague under Federal Rule of Civil Procedure 65(d), and shortened the proposed 15-year term to six years.

Two Judges, No Breakup

This is the second Google monopolization case to reach the remedies stage in as many years. In the first, the 2020 search case, Judge Amit Mehta of the District of Columbia found that Google had unlawfully maintained monopolies in general search services and general search text advertising through exclusive distribution agreements.

The government's remedies proposal in the Search case sought a Chrome divestiture, with Android divestiture contingent on whether the other remedies failed. Judge Mehta rejected both because the DOJ had not shown a significant causal connection between Chrome and the search monopoly he found and because the DOJ had not shown that behavioral remedies would be inadequate without it. He also concluded that separating a free product Google built from the ground up would be messy, lengthy, and risky for consumers.

Judge Brinkema followed that framework closely. She described the government's divestiture proposals as "a poor fit for this case," adopted Judge Mehta's assessment that a breakup would be "incredibly messy and highly risky," and applied the same Microsoft causal-connection test. She relied on his reasoning to reject vague anti-circumvention provisions and matched his six-year term. Both judges also emphasized that artificial intelligence is reshaping the markets before them.

The ad tech ruling adds something the Search ruling could not. Judge Mehta found that Google had unlawfully maintained its monopolies, whereas Judge Brinkema found that Google had unlawfully acquired and maintained them. She acknowledged that this made the structural question "arguably closer," and the government still did not prevail.

If divestiture does not follow from those facts, the bar for breakups in monopolization cases is high, as it should be. Both decisions follow the course the D.C. Circuit set in 2001 when it reversed the order breaking up Microsoft. Across three landmark cases, courts have reached the same conclusion: fix the unlawful conduct and supervise compliance.

Under the court's order, the parties have 30 days to submit a joint proposed final judgment, and appeals are likely.