Google has been ordered to loosen the restrictions that bind its advertising technology stack together and to operate under an independent antitrust compliance monitor for six years, after a US federal judge chose behavioural remedies over a structural break-up in one of the most closely watched monopolisation cases of the decade.
In a 106-page remedies opinion unsealed on 16 September 2026, US District Judge Leonie Brinkema of the Eastern District of Virginia declined to force Google to divest its AdX advertising exchange — the outcome the Department of Justice had argued was the only durable fix. Instead, she imposed a package of interoperability, data-access and non-discrimination obligations designed to give rival ad-tech providers a genuine route into markets Google has long dominated.
What the court ordered
The remedies target the technical advantages Google draws from owning several links in the ad-serving chain at once. Under the order, Google must enable integrations between AdX and the open-source header-bidding framework Prebid, and between its publisher ad server — DoubleClick for Publishers, now folded into Google Ad Manager — and Prebid. AdX must also send real-time bids to competing publisher ad servers rather than reserving that access for Google’s own tools.
Publishers, meanwhile, gain the right to extract and take their data out of DFP and AdX, lowering the switching costs that have kept many tied to Google’s products. On the buy side, Google’s AdWords business is barred from favouring AdX or other Google-owned ad-tech on the basis of common ownership, and may no longer bid directly into DFP.
Why the judge rejected a break-up
The Department of Justice had pressed for a structural remedy, arguing that only a forced sale of AdX would cure the harm and that conduct rules would be too easily gamed. Judge Brinkema disagreed, concluding that changes to Google’s business practices could provide sufficient access for competing ad-tech providers without dismantling the exchange. She also trimmed the government’s proposed timetable sharply: the DoJ had sought oversight lasting 15 years, but the measures will run for six.
A monitor with teeth
To police compliance, the court will install an independent monitor supported by a technical committee, operating under court supervision for the six-year term. That machinery — rather than a one-off divestiture — is what the ruling relies on to keep Google honest as it re-engineers how its products talk to competitors. The final judgment will fold in the behavioural restrictions and the monitoring structure the court has set out.
How the case got here
The proceedings, United States et al. v. Google LLC (case no. 1:23-cv-00108), were brought by the Department of Justice together with a coalition of US states under the Sherman Act. After a three-week liability trial, Judge Brinkema found in April 2025 that Google had unlawfully acquired and maintained monopoly power in two ad-tech markets — the open-web display publisher ad server and the ad exchange — in breach of Section 2, and had unlawfully tied its publisher ad server to AdX in breach of Sections 1 and 2.
Google was represented by Karen Dunn of Paul, Weiss, Rifkind, Wharton & Garrison, while Julia Tarver Wood led the Department of Justice trial team. The company has said it disagrees with the liability findings relating to Google Ad Manager and intends to appeal, maintaining that a forced sale would have hurt publishers and advertisers — especially smaller businesses that rely on its integrated tools. Associate Attorney General Stanley Woodward Jr said the department was studying the opinion and weighing its next steps, and framed the outcome as meaningful relief anchored in interoperability, data-sharing and non-discrimination.
Why it matters for advisers and in-house counsel
For competition practitioners, the significance lies in the method. Rather than reaching for divestiture — the classic structural cure — the court has tried to restore competition inside a digital platform by mandating interoperability, prising open data, forbidding self-preferencing and installing court-supervised monitoring. It is a template for regulating businesses whose products are so technically interlocked that separating them is difficult, and it will be read closely alongside parallel scrutiny of Google in Europe and elsewhere.
The open question is enforcement. Behavioural remedies live or die on implementation, and much will turn on how firmly the monitor and technical committee hold Google to the detail of integration, bidding and data portability — and on how the anticipated appeals reshape the final settlement. For publishers, advertisers and the ad-tech challengers who have spent years complaining about the plumbing of the open web, the value of this ruling will be measured not in the opinion’s language but in whether rivals can actually plug in.
