Google argues DOJ ad tech breakup risks business disruption

Google concluded its advertising technology remedies trial on November 21, 2025, with testimony highlighting potential disruption and uncertainty that could result from the Department of Justice's proposal to force divestiture of Google Ad Manager. The trial's final day featured statements from independent companies, small business owners, and technology executives describing how proposed structural changes could affect their operations.

The remedies phase follows Judge Leonie Brinkema's April 17, 2025 ruling that Google illegally monopolized publisher ad server and ad exchange markets. The Department of Justice seeks forced sale of Google's AdX advertising exchange and potential divestiture of its publisher ad server, while Google proposes behavioral changes including direct connections between rival ad servers and its exchange.

James Avery, chief executive of rival ad server Kevel, testified during the proceedings that a direct, non-preferential connection to Google's exchange would resolve concerns identified in the case. His testimony suggests that technical modifications rather than complete separation could address competitive issues. Professor Robin Lee, the DOJ's lead economist, admitted that divestiture would not be needed if behavioral remedies were properly crafted and enforced, according to Google's November 21 statement.

The technical complexity of separating Google's integrated advertising technology emerged as a central issue. Professor Jason Nieh, testifying as a Google expert, characterized the proposed breakup as a highly complicated software engineering undertaking with no guarantee of success. Glenn Bernston, director of engineering for Ad Manager, stated during testimony that "It makes no sense. One can build it, but it won't work," referring to the DOJ's divestiture proposal.

Small business representatives testified about potential operational impacts. Jeff Taxdahl, founder of Thread Logic, explained concerns about fragmented systems during the trial. "If Google's ad tech tools are broken, it's not clear what will take their place. A fragmented system would lack Google's reach and efficiency, so we'd have to spend far more time managing multiple ad and analytics platforms. Our ads would be more expensive — but less effective. That's a one-two punch for America's businesses," Taxdahl stated.

wikiHow chief executive Elizabeth Douglas told the court about revenue concerns. "I'm here today because I'm worried for my business... we require the revenue that we get from our advertising to innovate and to run our business and it scares me to think that it is going to potentially be changing," Douglas testified. She added that "there's just no SSP that I trust as much as Google, in particular with the consistency that Google pays us every month and supports us with our problems."

Pinterest chief executive Bill Ready addressed whether breaking up Google would restore competition to advertising markets. According to his testimony, "a new owner with different incentives—especially one dominant on the buy side or an AI platform optimizing for unknown objectives—could recreate the same dynamics in a new form. And holding that successor accountable could take years."

The trial concluded following November 3, 2025 filings where both parties submitted final post-trial briefs. The DOJ's 44-page brief proposed complete divestiture of AdX within 12 months, open-sourcing of auction logic, and potential contingent divestiture of remaining publisher ad server components. Google's 43-page filing proposed behavioral remedies including real-time bid sharing with rival ad servers, removal of discriminatory pricing rules, and appointment of a monitoring trustee for six years.

Ravi Goel, chief executive of PubMatic, testified about market dynamics during the proceedings. According to Google's statement, Goel described advertising technology as evolving "at a very high pace ... a relentless pace of change," emphasizing ongoing competitive pressure in the sector.

The remedies trial follows a three-week liability trial concluded in September 2024 and featured 19 fact witnesses and seven expert witnesses during September 22 through early October 2025 proceedings. Testimony included publishers such as Daily Mail and WikiHow, ad exchange executives from Index Exchange and PubMatic, and technical experts addressing implementation feasibility.

The competing remedy proposals reflect fundamentally different approaches to addressing monopolization findings. The Department of Justice argues that structural separation is necessary because Google's integrated control across multiple sides of advertising transactions creates inherent conflicts of interest. The government contends that behavioral remedies would require courts to become central planners of advertising technology markets, exceeding practical limits of judicial administration.

Google maintains that behavioral changes directly address the court's findings without creating operational uncertainty for businesses that depend on its advertising tools. The company argues that no divestiture has been ordered to remedy product tying in previous antitrust cases, and that separating integrated technology assets represents unprecedented complexity in antitrust enforcement.

Technical testimony during the remedies trial addressed specific implementation challenges. Internal Google documents from Projects Sunday, Monday, and 2023-2024 technical evaluations were presented as evidence. Tim Craycroft, Google's vice president in charge of display products, testified about feasibility studies and expressed openness to extending monitoring periods beyond three years.

The case represents the second successful monopolization lawsuit the Department of Justice has brought against Google. In August 2024, a separate federal court ruled that Google illegally maintained a monopoly in online search and search advertising markets. The advertising technology case was filed January 24, 2023, by the Justice Department and attorneys general from 17 states.

Judge Brinkema expressed skepticism about AdX divestiture timelines during closing arguments on November 21, 2025. Her questions focused heavily on implementation schedules and practical realities, suggesting concern about commercial urgency. She indicated that a ruling would arrive in January or February 2026, though additional arguments might occur before final judgment.

The proceedings have attracted significant attention from advertising technology companies, publishers, and advertisers. Private litigation by publishers and advertisers seeking damages has accelerated following the liability finding, with courts applying issue preclusion that allows plaintiffs to proceed directly to calculating financial harm without re-proving monopolization.

For marketing professionals, the case creates uncertainty about future advertising infrastructure. Publishers who testified during earlier proceedings described inability to switch away from Google despite dissatisfaction with certain practices. The potential for structural remedies raises questions about which companies possess sufficient resources and expertise to operate large-scale advertising technology platforms if divestiture is ordered.

The Department of Justice and state plaintiffs argue that only structural changes can satisfy four mandatory objectives of antitrust remedies: unfettering markets from anticompetitive conduct, terminating illegal monopolies, denying defendants the fruits of violations, and ensuring no practices likely to result in future monopolization. The government identified numerous potential methods for re-monopolization including manipulating latency, altering data signals, modifying decision algorithms, implementing differential pricing, creating new exclusive relationships, restricting transaction types, and limiting bid volume.

Google's proposal includes commitments to make real-time AdX bids available to rival publisher ad servers, remove Unified Pricing Rules that restrict publishers' pricing flexibility, commit not to rebuild First Look or Last Look features that gave Google's exchange preferential treatment, and accept monitoring by an independent trustee. The company updated its proposal during trial to formalize commitments ensuring these integrations would function properly.

The trial examined global implications of proposed remedies. Google simultaneously faces European Commission antitrust proceedings where it submitted a formal response on November 13, 2025, rejecting structural remedies and proposing product changes similar to those offered in the United States case. The dual proceedings represent coordinated regulatory pressure on Google's advertising technology business across jurisdictions.

Technical experts testified about monitoring challenges associated with behavioral remedies. Ongoing oversight of algorithmic decision-making in real-time advertising auctions presents substantial complexity. Google's integration of advertising technology with broader cloud infrastructure complicates compliance efforts, requiring extensive coordination across Search, YouTube, and Google Cloud Platform.

The outcome will influence how antitrust law is applied to other technology platforms that dominate their respective markets. The case marks a significant moment in enforcement against technology companies, coming after decades where major antitrust actions against dominant platforms were relatively rare.

Timeline

• January 24, 2023: Department of Justice files antitrust lawsuit against Google targeting advertising technology practices
• September 2024: Three-week liability trial concludes with extensive technical testimony
• April 17, 2025: Judge Brinkema rules Google monopolized digital advertising markets
• August 15, 2025: Court documents reveal extensive witness lists and exhibits for remedies trial
• September 22-October 2025: Remedies trial presents testimony from industry participants
• October 27, 2025: Southern District of New York grants summary judgment to private plaintiffs using Virginia findings
• November 3, 2025: DOJ and Google file final post-trial briefs and proposed remedies
• November 21, 2025: Remedies trial concludes with final testimony
• Expected January-February 2026: Judge Brinkema's ruling anticipated

Summary

Who: The United States Department of Justice, 17 state attorneys general, and Google LLC participated in the remedies trial. Witnesses included small business owner Jeff Taxdahl of Thread Logic, wikiHow CEO Elizabeth Douglas, Pinterest CEO Bill Ready, PubMatic CEO Ravi Goel, Kevel CEO James Avery, Google expert Professor Jason Nieh, DOJ economist Professor Robin Lee, and Ad Manager director of engineering Glenn Bernston. Judge Leonie Brinkema presides over the Eastern District of Virginia proceedings.

What: The remedies trial concluded with testimony addressing the Department of Justice's proposal to force divestiture of Google's advertising exchange and publisher ad server versus Google's proposed behavioral changes. Witnesses described potential business disruption, technical implementation challenges, revenue concerns, and competitive dynamics. The proceedings followed the April 17, 2025 liability finding that Google illegally monopolized publisher ad server and ad exchange markets.

When: The remedies trial testimony concluded November 21, 2025, following proceedings from September 22 through early October 2025. The case began with the January 24, 2023 antitrust lawsuit filing. Judge Brinkema's ruling is expected between January and February 2026.

Where: The Eastern District of Virginia federal court in Alexandria heard the remedies phase proceedings. The case affects advertising technology markets globally, with implications for publishers, advertisers, and technology companies worldwide. Parallel proceedings are occurring in the European Union where Google faces similar structural remedy demands.

Why: The remedies trial addresses how to restore competition in digital advertising markets following findings that Google violated the Sherman Act through monopolization. The Department of Justice seeks structural separation to eliminate conflicts of interest created by Google's control across multiple sides of advertising transactions. Google argues that behavioral modifications can address competitive concerns without creating operational disruption for businesses dependent on its advertising technology tools.