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Areas of Expertise :
Advertising, Antitrust, Economics, Computer Science, Pricing, Software Engineering, Marketing
Published Date:
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Jurisdiction:
Federal. Fourth Circuit
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United States et al. v. Google LLC is a federal antitrust case concerning Google's role in the technology used to buy and sell open-web display advertising. The U.S. Department of Justice and state plaintiffs challenged Google's control of DoubleClick for Publishers, known as DFP, its AdX advertising exchange, and related practices affecting publishers, advertisers, and competing ad tech companies. The government alleged that Google used its position across connected advertising tools to restrict competition in publisher ad server and ad exchange markets.
Following a bench trial, U.S. District Judge Leonie M. Brinkema found Google liable under Sections 1 and 2 of the Sherman Act for conduct involving two ad tech markets. The court determined that Google maintained monopoly power in open-web display publisher ad servers and open-web display ad exchanges and unlawfully tied DFP to AdX. The government did not prevail on its proposed advertiser ad network market. The litigation later moved to a remedies proceeding addressing structural and behavioral relief.
The U.S. Department of Justice and eight states filed a civil antitrust lawsuit against Google in the U.S. District Court for the Eastern District of Virginia. The complaint accused Google of monopolizing digital advertising technology markets through acquisitions, contractual restrictions, product integrations, and other practices affecting publishers and advertisers. The plaintiffs brought claims under Sections 1 and 2 of the Sherman Act and sought structural and other forms of relief involving Google's ad tech operations.
Nine additional states joined the lawsuit through an amended complaint, bringing the number of state plaintiffs to 17. The additional states were Arizona, Illinois, Michigan, Minnesota, Nebraska, New Hampshire, North Carolina, Washington, and West Virginia. On April 28, 2023, Judge Brinkema denied Google's motion to dismiss, allowing the litigation to proceed through fact and expert discovery.
A bench trial began before Judge Brinkema in Alexandria, Virginia. Testimony addressed DFP, AdX, Google Ads demand, market definition, auction mechanics, pricing, barriers to entry, First Look, and Last Look. Plaintiffs' market-definition expert Dr. Robin Lee testified about publisher ad servers and ad exchanges, while Google's expert Dr. Mark Israel challenged portions of the government's proposed market definitions. Plaintiffs also presented expert testimony from Ramamoorthi Ravi and Rosa Abrantes-Metz concerning Google's auction practices and their competitive effects.
After approximately three weeks of trial testimony and later briefing, the parties presented closing arguments. The government argued that Google's control of connected advertising products restricted competition and reinforced its positions in publisher ad servers and ad exchanges. Google disputed the government's market definitions and maintained that its integrations and auction changes reflected competition and product improvements rather than unlawful exclusionary conduct. Judge Brinkema then took the case under submission.
Judge Brinkema ruled that Google violated Section 2 of the Sherman Act by willfully acquiring and maintaining monopoly power in the markets for open-web display publisher ad servers and open-web display ad exchanges. She also ruled that Google's tying of DFP to AdX violated Sections 1 and 2. First Look, Last Look, and other changes to Google's sell-side advertising technology were included in the court's findings concerning exclusionary conduct.
The plaintiffs did not establish their proposed advertiser ad network market. They also did not prove that Google's acquisitions of DoubleClick and AdMeld themselves constituted anticompetitive conduct.
The plaintiffs submitted a revised remedies proposal seeking structural, behavioral, and administrative relief. They called for divestiture of AdX and proposed a phased approach for DFP that included interoperability requirements, open-sourcing its final-auction logic, and possible later divestiture of the remaining publisher ad server business. Other provisions addressed Google's treatment of competing exchanges and advertising buying tools.
Under the proposal, a later DFP divestiture could have been avoided if an assessment showed that the earlier remedies had restored sufficient competition.
The evidentiary remedies hearing began on September 22, 2025, and concluded on October 6 after 11 days of proceedings. Testimony covered the proposed sale of AdX, possible DFP changes, interoperability, open-source auction technology, publisher migration, and the technical and economic effects of the requested relief. Economists, technical specialists, industry participants, and other witnesses addressed how the proposed remedies could affect Google's advertising technology operations and competing ad tech systems.
The parties returned to court for closing arguments on the appropriate remedies. The plaintiffs continued to seek structural and behavioral measures addressing the antitrust violations identified in the April 2025 liability ruling. Google opposed divestiture and advocated less disruptive behavioral measures.
Judge Brinkema declined to order Google to divest AdX and rejected the proposed structural breakup of its advertising technology operations. The court also rejected the proposed open-sourcing of DFP's final-auction logic and the contingent divestiture of the remaining DFP business. Instead, the court accepted most of the parties' proposed behavioral remedies, with modifications, while allowing Google to retain AdX and DFP. The parties were directed to prepare a proposed final judgment reflecting the court's remedies decisions.
United States District Court for the Eastern District of Virginia
Case Name:
United States et al. v. Google LLC
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United States et al. v. Google LLC is a federal antitrust case concerning Google's role in the technology used to buy and sell open-web display advertising. The U.S. Department of Justice and state plaintiffs challenged Google's control of DoubleClick for Publishers, known as DFP, its AdX advertising exchange, and related practices affecting publishers, advertisers, and competing ad tech companies. The government alleged that Google used its position across connected advertising tools to restrict competition in publisher ad server and ad exchange markets.
Following a bench trial, U.S. District Judge Leonie M. Brinkema found Google liable under Sections 1 and 2 of the Sherman Act for conduct involving two ad tech markets. The court determined that Google maintained monopoly power in open-web display publisher ad servers and open-web display ad exchanges and unlawfully tied DFP to AdX. The government did not prevail on its proposed advertiser ad network market. The litigation later moved to a remedies proceeding addressing structural and behavioral relief.
The U.S. Department of Justice and eight states filed a civil antitrust lawsuit against Google in the U.S. District Court for the Eastern District of Virginia. The complaint accused Google of monopolizing digital advertising technology markets through acquisitions, contractual restrictions, product integrations, and other practices affecting publishers and advertisers. The plaintiffs brought claims under Sections 1 and 2 of the Sherman Act and sought structural and other forms of relief involving Google's ad tech operations.
Nine additional states joined the lawsuit through an amended complaint, bringing the number of state plaintiffs to 17. The additional states were Arizona, Illinois, Michigan, Minnesota, Nebraska, New Hampshire, North Carolina, Washington, and West Virginia. On April 28, 2023, Judge Brinkema denied Google's motion to dismiss, allowing the litigation to proceed through fact and expert discovery.
A bench trial began before Judge Brinkema in Alexandria, Virginia. Testimony addressed DFP, AdX, Google Ads demand, market definition, auction mechanics, pricing, barriers to entry, First Look, and Last Look. Plaintiffs' market-definition expert Dr. Robin Lee testified about publisher ad servers and ad exchanges, while Google's expert Dr. Mark Israel challenged portions of the government's proposed market definitions. Plaintiffs also presented expert testimony from Ramamoorthi Ravi and Rosa Abrantes-Metz concerning Google's auction practices and their competitive effects.
After approximately three weeks of trial testimony and later briefing, the parties presented closing arguments. The government argued that Google's control of connected advertising products restricted competition and reinforced its positions in publisher ad servers and ad exchanges. Google disputed the government's market definitions and maintained that its integrations and auction changes reflected competition and product improvements rather than unlawful exclusionary conduct. Judge Brinkema then took the case under submission.
Judge Brinkema ruled that Google violated Section 2 of the Sherman Act by willfully acquiring and maintaining monopoly power in the markets for open-web display publisher ad servers and open-web display ad exchanges. She also ruled that Google's tying of DFP to AdX violated Sections 1 and 2. First Look, Last Look, and other changes to Google's sell-side advertising technology were included in the court's findings concerning exclusionary conduct.
The plaintiffs did not establish their proposed advertiser ad network market. They also did not prove that Google's acquisitions of DoubleClick and AdMeld themselves constituted anticompetitive conduct.
The plaintiffs submitted a revised remedies proposal seeking structural, behavioral, and administrative relief. They called for divestiture of AdX and proposed a phased approach for DFP that included interoperability requirements, open-sourcing its final-auction logic, and possible later divestiture of the remaining publisher ad server business. Other provisions addressed Google's treatment of competing exchanges and advertising buying tools.
Under the proposal, a later DFP divestiture could have been avoided if an assessment showed that the earlier remedies had restored sufficient competition.
The evidentiary remedies hearing began on September 22, 2025, and concluded on October 6 after 11 days of proceedings. Testimony covered the proposed sale of AdX, possible DFP changes, interoperability, open-source auction technology, publisher migration, and the technical and economic effects of the requested relief. Economists, technical specialists, industry participants, and other witnesses addressed how the proposed remedies could affect Google's advertising technology operations and competing ad tech systems.
The parties returned to court for closing arguments on the appropriate remedies. The plaintiffs continued to seek structural and behavioral measures addressing the antitrust violations identified in the April 2025 liability ruling. Google opposed divestiture and advocated less disruptive behavioral measures.
Judge Brinkema declined to order Google to divest AdX and rejected the proposed structural breakup of its advertising technology operations. The court also rejected the proposed open-sourcing of DFP's final-auction logic and the contingent divestiture of the remaining DFP business. Instead, the court accepted most of the parties' proposed behavioral remedies, with modifications, while allowing Google to retain AdX and DFP. The parties were directed to prepare a proposed final judgment reflecting the court's remedies decisions.
An antitrust economics expert witness may analyze market definition, monopoly power, competitive effects, barriers to entry, substitution, and pricing. This expertise can help evaluate whether business practices restrict competition within defined advertising technology markets.
An auction theory and market design expert witness may assess how digital advertising auctions are structured and how their rules affect publishers, exchanges, and advertiser buying tools. Relevant analysis may include bidding mechanisms, auction sequencing, information advantages, and competitive outcomes.
A computer science and optimization expert witness may examine the technical operation of automated advertising systems, including bid processing, auction logic, algorithms, and system interactions. This expertise can help explain how advertising technologies function and how technical design choices affect auction outcomes.
An economic pricing and damages expert witness may evaluate pricing behavior, publisher revenue, transaction fees, market effects, and financial harm associated with challenged business practices. Such analysis may also address economic impact, competitive pricing, and damages methodologies when monetary claims are involved.
DFP, or DoubleClick for Publishers, is publisher ad server software used to manage advertising inventory and determine which advertisements are served on publishers' websites. Google later incorporated DFP into Google Ad Manager.
AdX is Google's advertising exchange, where publisher advertising inventory is offered to advertiser buying tools through automated, real-time auctions. Publishers using DFP could access advertiser demand available through AdX within Google's sell-side advertising system.
Open-web display advertising generally refers to display advertising sold on third-party websites across the open web, as distinguished from advertising within closed or "walled garden" platforms and certain other digital advertising environments. The antitrust findings addressed specific open-web display publisher ad server and ad exchange markets rather than the entire digital advertising industry.
First Look gave AdX an early opportunity to compete for publisher inventory before certain rival exchanges participated. Last Look allowed AdX to respond after receiving information about competing bids before determining whether it could submit a winning bid. Both practices were examined as part of Google's conduct involving digital advertising auctions.
The government sought structural and behavioral relief after the liability ruling. Structural proposals included divestiture of AdX, open-sourcing DFP's final-auction logic, and possible later divestiture of the remaining DFP publisher ad server business. Behavioral proposals addressed Google's future conduct and its interactions with competing advertising technologies.
The court found Google liable for monopolization in the markets for open-web display publisher ad servers and open-web display ad exchanges and for unlawfully tying DFP to AdX. The government did not establish its proposed advertiser ad network market, and the plaintiffs did not prove that Google's acquisitions of DoubleClick and AdMeld themselves constituted anticompetitive conduct.
The remedies phase produced a narrower outcome than the structural relief requested by the government. On September 2, 2026, Judge Brinkema rejected divestiture of AdX, open-sourcing of DFP's final-auction logic, and the proposed contingent divestiture of the remaining DFP business. The court instead accepted most of the proposed behavioral remedies with modifications and directed the parties to prepare a proposed final judgment reflecting those requirements.
What antitrust laws did Google violate?
Google was found liable under Sections 1 and 2 of the Sherman Act. The violations involved monopolization in open-web display publisher ad server and ad exchange markets and the unlawful tying of DFP to AdX.
Did the court order Google to sell AdX?
No, Judge Brinkema declined to require Google to divest AdX. The court also rejected open-sourcing DFP's final-auction logic and the proposed contingent divestiture of the remaining DFP business, choosing behavioral remedies instead.
What types of expert witnesses testified in the Google ad tech case?
The parties presented experts in antitrust economics, auction theory, market design, computer science, optimization, pricing, and economic analysis. Their testimony addressed market definition, competition, auction systems, pricing, and the operation of digital advertising technology.
Did the DOJ win every claim against Google?
No, the government did not prevail on every claim or theory. The plaintiffs failed to establish their proposed open-web display advertiser ad network market and did not prove that Google's acquisitions of DoubleClick and AdMeld themselves constituted anticompetitive conduct.
An antitrust economics expert witness may analyze market definition, monopoly power, competitive effects, barriers to entry, substitution, and pricing. This expertise can help evaluate whether business practices restrict competition within defined advertising technology markets.
An auction theory and market design expert witness may assess how digital advertising auctions are structured and how their rules affect publishers, exchanges, and advertiser buying tools. Relevant analysis may include bidding mechanisms, auction sequencing, information advantages, and competitive outcomes.
A computer science and optimization expert witness may examine the technical operation of automated advertising systems, including bid processing, auction logic, algorithms, and system interactions. This expertise can help explain how advertising technologies function and how technical design choices affect auction outcomes.
An economic pricing and damages expert witness may evaluate pricing behavior, publisher revenue, transaction fees, market effects, and financial harm associated with challenged business practices. Such analysis may also address economic impact, competitive pricing, and damages methodologies when monetary claims are involved.
DFP, or DoubleClick for Publishers, is publisher ad server software used to manage advertising inventory and determine which advertisements are served on publishers' websites. Google later incorporated DFP into Google Ad Manager.
AdX is Google's advertising exchange, where publisher advertising inventory is offered to advertiser buying tools through automated, real-time auctions. Publishers using DFP could access advertiser demand available through AdX within Google's sell-side advertising system.
Open-web display advertising generally refers to display advertising sold on third-party websites across the open web, as distinguished from advertising within closed or "walled garden" platforms and certain other digital advertising environments. The antitrust findings addressed specific open-web display publisher ad server and ad exchange markets rather than the entire digital advertising industry.
First Look gave AdX an early opportunity to compete for publisher inventory before certain rival exchanges participated. Last Look allowed AdX to respond after receiving information about competing bids before determining whether it could submit a winning bid. Both practices were examined as part of Google's conduct involving digital advertising auctions.
The government sought structural and behavioral relief after the liability ruling. Structural proposals included divestiture of AdX, open-sourcing DFP's final-auction logic, and possible later divestiture of the remaining DFP publisher ad server business. Behavioral proposals addressed Google's future conduct and its interactions with competing advertising technologies.
The court found Google liable for monopolization in the markets for open-web display publisher ad servers and open-web display ad exchanges and for unlawfully tying DFP to AdX. The government did not establish its proposed advertiser ad network market, and the plaintiffs did not prove that Google's acquisitions of DoubleClick and AdMeld themselves constituted anticompetitive conduct.
The remedies phase produced a narrower outcome than the structural relief requested by the government. On September 2, 2026, Judge Brinkema rejected divestiture of AdX, open-sourcing of DFP's final-auction logic, and the proposed contingent divestiture of the remaining DFP business. The court instead accepted most of the proposed behavioral remedies with modifications and directed the parties to prepare a proposed final judgment reflecting those requirements.
What antitrust laws did Google violate?
Google was found liable under Sections 1 and 2 of the Sherman Act. The violations involved monopolization in open-web display publisher ad server and ad exchange markets and the unlawful tying of DFP to AdX.
Did the court order Google to sell AdX?
No, Judge Brinkema declined to require Google to divest AdX. The court also rejected open-sourcing DFP's final-auction logic and the proposed contingent divestiture of the remaining DFP business, choosing behavioral remedies instead.
What types of expert witnesses testified in the Google ad tech case?
The parties presented experts in antitrust economics, auction theory, market design, computer science, optimization, pricing, and economic analysis. Their testimony addressed market definition, competition, auction systems, pricing, and the operation of digital advertising technology.
Did the DOJ win every claim against Google?
No, the government did not prevail on every claim or theory. The plaintiffs failed to establish their proposed open-web display advertiser ad network market and did not prove that Google's acquisitions of DoubleClick and AdMeld themselves constituted anticompetitive conduct.
Algorithm Development
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Quantitative analysis
Market Research
Online Marketing
Web Applications