The remedies phase of United States v. Google LLC — the ad tech case in the Eastern District of Virginia — has now become the most consequential antitrust proceeding in the digital economy. In April 2025, Judge Leonie Brinkema ruled that Google had unlawfully monopolized two markets central to the open web: the publisher ad server market (where Google's DFP/Google Ad Manager dominates) and the ad exchange market (AdX). The Department of Justice is reportedly pressing for structural remedies, including a forced divestiture of Google Ad Manager. As of May 2026, briefing and hearings on remedies are ongoing, and the court's choices will shape how billions of dollars in digital advertising are intermediated for years to come.
We agree with the court on the diagnosis. Google's conduct — tying its publisher ad server to its exchange, manipulating auction dynamics, and locking publishers into a vertically integrated stack — degraded competition on the supply side of programmatic advertising. The question now is not whether to act, but how. And here, the temptation to reach for the bluntest tool in the antitrust toolkit deserves scrutiny.
Why structural remedies are tempting — and risky
Structural separation is intuitively appealing. It promises a clean break: spin out Google Ad Manager, end the conflicts of interest, and let competition do the rest. The DOJ's 2024 Sherman Act case against Google Search, and the European Commission's parallel 2023 statement of objections on ad tech, both flirted with similar logic. The Commission, notably, said in 2023 that only divestiture would likely resolve the conflicts it identified.
But ad tech is not telecoms in 1984, and Google Ad Manager is not a long-haul fiber network. Programmatic advertising is a software stack built on tightly integrated APIs, real-time bidding infrastructure, fraud detection, and machine-learning models trained on years of auction data. Forced divestiture raises hard, under-discussed questions:
- Who buys the spun-off entity? The natural buyers — other large platforms — would simply concentrate the market elsewhere. A private-equity buyer optimizing for short-term yield may strip investment from infrastructure that publishers depend on.
- What about publishers caught in the transition? Newspapers, independent sites, and small publishers run on thin margins. A multi-year migration window with degraded auction performance could push marginal publishers out of business — the opposite of what an ad tech remedy is supposed to achieve.
- Will it actually restore competition? Markets remain concentrated when scale economies and data network effects are intrinsic. Splitting the firm without addressing the underlying dynamics may just create two dominant firms instead of one.
Behavioral remedies have a bad reputation they don't fully deserve
Conventional wisdom holds that behavioral remedies — conduct rules policed by a monitor or technical committee — are weak because they require ongoing oversight and are easy to circumvent. The 2001 Microsoft consent decree is often cited as the cautionary tale. But that decree did, in fact, open space for browser competition, web standards, and ultimately the cloud and mobile era. Antitrust does not need to deliver a knockout blow to be effective; it needs to keep the door open.
A proportionate remedy package in U.S. v. Google could include:
- Auction integrity rules: mandatory first-price auctions, prohibitions on last-look advantages, and transparency on bid-shading and fee structures across the stack.
- Interoperability for publishers: open APIs for Google Ad Manager so publishers can route inventory to rival exchanges on equal terms, with non-discrimination obligations enforced by a technical monitor.
- Data portability: publishers should be able to take their historical performance data with them when they switch ad servers — the same logic that animates Article 6 of the EU Digital Markets Act.
- A sunset clause and review: if conduct remedies fail to restore measurable competition within, say, five years, the court retains authority to revisit structural relief.
What's at stake for the open web
Digital advertising funds an enormous share of the journalism, independent publishing, and free services that comprise the open internet. The IAB and eMarketer have for years estimated US digital ad spending in the hundreds of billions annually, with programmatic accounting for the large majority. Whatever remedy the court adopts will ripple through this entire stack — affecting not just Google's revenue, but the economics of every publisher and advertiser that uses programmatic channels.
The goal of antitrust is not to punish successful firms, but to keep markets contestable. A remedy that destabilizes the plumbing of the open web while a competitor is built from scratch fails that test.
The pro-innovation path
Judge Brinkema deserves credit for a careful liability ruling that named specific conduct and specific harms. The remedies phase should match that precision. Forcing a divestiture that the market cannot cleanly absorb risks turning a competition victory into a publisher catastrophe — and would invite years of appeals that delay any relief at all.
A package built around auction transparency, interoperability, data portability, and a credible review mechanism would address the conduct the court found unlawful, give rival ad tech firms — many of which are well-capitalized and innovative — a real shot at growth, and avoid the collateral damage of a forced break-up. That is the proportionate, evidence-based path, and it is the one that best protects the users, publishers, and advertisers who ultimately bear the cost of getting this wrong.