On September 2, Judge Leonie M. Brinkema of the US District Court for the Eastern District of Virginia issued a sealed decision in Google's second American antitrust case, this time centring on the company's grip over ad tech on the open web. Rather than ordering a breakup, the 106-page ruling—made public on September 16—favoured behavioral fixes over the structural divestitures that the US Department of Justice had sought.
The judgment creates a potential fork in the road between American and European enforcement. Since 2021, the European Commission has been examining Google's advertising technology monopoly in a case with substantial overlap to the US litigation. Brussels has signalled that structural remedies, including asset sales, might prove necessary to resolve Google's inherent conflicts of interest.
The question now looms: can the EU still move forward with a breakup—and would such a remedy work in practice if imposed only in Europe?
The US rejects a breakup
The DOJ filed its case in 2023, charging Google with "monopolizing multiple digital advertising technology products in violation of Sections 1 and 2 of the Sherman Act." The litigation examined Google's reach across the entire ad tech chain: publisher ad servers (DoubleClick for Publishers), advertiser platforms (Google Ads) and the exchange connecting buyers and sellers of digital advertising (AdX). The court determined that Google had illegally held monopoly power in publisher ad server and ad exchange markets, though it rejected the government's allegations regarding the advertiser ad network sector.
The probe focused on Google's acquisition strategy to gain control of critical ad tech infrastructure used by website publishers to monetise advertising space. Google's 2008 purchase of DoubleClick stood at the heart of the DOJ's argument, as it consolidated essential components of the ad tech ecosystem under one roof, enabling Google to dominate publisher ad servers, exchanges and ancillary tools.
The government contended that Google had effectively bundled access to its advertiser base and AdX with DoubleClick. Brinkema found that Google had unlawfully tied its publisher ad server and exchange, leveraging that tie to sustain monopoly power. Trial testimony revealed that "publishers simply had to be on [DoubleClick for Publishers] because it was the only way to fully access the large base of advertisers in Google's ad network through Google's AdX exchange."
After trial, the judge concluded Google had illegally preserved monopoly control over two advertising market segments—the publisher side and the exchange—while dismissing claims about the advertiser side, "saying the government had failed to prove that it constituted a real and defined market." Both parties then submitted remedies proposals.
Behavioral remedies instead of divestiture
The DOJ sought to force Google to divest its ad exchange and publisher ad server, which would become open source and operate under independent management. The government also proposed other measures, including an escrow fund financed by Google, plus behavioral requirements such as compatibility with competing exchanges and enhanced price transparency for publishers and advertisers. Google opposed structural remedies but offered its own behavioral solutions.
In the September 16 decision, the judge imposed behavioral remedies while declaring that breaking up Google's ad tech division was "neither realistic nor needed." To reverse Google's policies tying DoubleClick to AdX, the judge mandated that Google enable its services to work with competitors, specifically requiring integration with Prebid, the leading header bidding provider.
Header bidding is a method where websites embed JavaScript code in their page headers to direct ad inventory to multiple exchanges before routing to Google. Though the technique emerged in 2014, its ability to challenge Google's dominance faced multiple obstacles, notably Google's Unified Pricing Rules—"a price parity condition prohibiting publishers from routing their ads through Google's exchange at prices higher than they route them through competing exchanges." The DOJ established that this pricing rule was deliberately designed to neutralise header bidding as a competitive threat.
The judge has ordered Google "to deprecate and not reimplement Unified Pricing Rules in DFP for all indirect transaction types," thereby enabling alternative exchanges to compete more effectively. Google must also cease using First Look and Last Look functionality. Last Look allowed Google to observe winning bids from other exchanges and submit a marginally higher offer at the final moment. Although header bidding technically bypassed Google's exchanges, Google's dominance in the publisher ad server market meant information could still flow to its own exchange and "displace trades by a penny." Eliminating these mechanisms aims to "restore[...] competition in the ad exchange market."
Google must furnish publishers with "historical and configuration data" from DoubleClick and ongoing AdX bid information, and must permit publishers to move that data to competing publisher ad servers. The company faces a ban on discriminatory bidding, with implementation details to be negotiated between Google and the DOJ.
Additionally, "Google ads will be prohibited from favoring Google-owned or Google-affiliated ad tech tools when bidding for indirect open-web display ad inventory," and Google's deployment of first-party data (derived from YouTube and similar properties) will be restricted "when bidding for indirect open-web display ad inventory." This acknowledges the information imbalance benefiting Google through its sprawling ecosystem. Google must also install an internal compliance monitor.
Brinkema's reasoning partly rests on the premise that Google's ad tech infrastructure is too deeply intertwined for divestiture to function as a workable solution. This poses a particular challenge for Brussels, whose inquiry addresses comparable conduct but has not ruled out structural remedies.
Brussels faces a difficult choice
The Commission's 2021 investigation mirrors most of the abuses examined in the US case. Brussels alleges that Google has prioritised its own ad tech offerings to harm rivals, and in 2025 levied a €2.95 billion fine against the company for abusing its ad tech dominance. The Commission instructed Google to eliminate its conflict of interest and cease preferring its own exchange within 60 days, while cautioning that structural remedies would likely follow. Google submitted a proposal to address the Commission's objections last November, but the Commission extended the deadline.
Despite the cases' similarities, the US administration has threatened economic retaliation should another jurisdiction penalise American technology firms. Reports suggest the Commission postponed the fine due to concerns about tariffs and measures from the Trump administration. Competition chief Teresa Ribera had maintained a forceful stance, declaring that "it appears that the only way for Google to end its conflict of interest effectively is with a structural remedy, such as selling some part of its Adtech business," and that the Commission "will continue to apply our rules firmly and fairly, without fear or favor, in relation to all companies operating in Europe."
Following the US ruling, Ribera has signalled that the EU "should try to stay consistent with authorities elsewhere." Yet some parliamentarians have reportedly urged the Commission "to preserve the option of structural remedies against Google, and that Brussels should not necessarily follow the approach taken by a US court." The challenge remains whether imposing structural remedies is feasible for the European Commission, both from technical and political standpoints.
Can Brussels go farther?
Multiple competing considerations complicate the picture. First, EU law imposes stringent proportionality requirements for structural remedies, making breakups uncommon. The EU also possesses less experience with such measures than the US, despite potential shortcomings in the American court-based system.
Second, the Commission's competition department chief has indicated the case presents challenges, involving "businesses that have already been fully integrated following an acquisition," whose separation would be "difficult to implement." Google has held dominance across the ad tech stack since acquiring DoubleClick in 2008. The stack's components no longer function as separate entities and have long been intertwined and sold together.
Brinkema's unsealed judgment echoed this concern, determining that the stack is too integrated and a divestiture would generate excessive "uncertainty" about future functionality, noting that this "is especially concerning because the stakes are high: this is 'technology that absolutely has to work for customers'."
Technical obstacles intensify when the two jurisdictions diverge. As Jacob Parry reported for Politico, Google's "buying tools, selling tools and the exchange between them run as one global system. A sale ordered by Brussels would apply on one side of the Atlantic, in a market where the largest advertisers and publishers don't stop at the EU's borders." Arielle Garcia, chief operating officer of Check My Ads, a US watchdog, told Politico that "while a Europe-only remedy might be technically possible, its effect would be minimal."
Parry reported that "several people involved in the complaint said privately that they no longer see a viable way to carve out and sell part of a US company's business within Europe alone, and are now pushing for the strongest measures the Commission can realistically deliver."
Max Bank, EU Competition Lead at Rebalance Now, told Tech Policy Press that an EU breakup order appears less probable, though he rejected the argument that technical complexity prevents divestiture, attributing this instead to political will. An EU-only structural remedy could also generate additional tensions with Washington, which has already signalled trade retaliation in response to EU action against American technology companies. The threat carries weight; the US represents the EU's largest trading partner, generating roughly €1.77 trillion in value in 2025.
Tim Cowen, Chair of the Antitrust Practice at Preiskel & Co, told Tech Policy Press that while divestiture can work, this case demands careful examination of how advertisers and publishers can access alternatives, which may not require a breakup. He stresses the importance of reviving competing options by "empowering" the advertiser to circumvent Google.
"AdX isn't anything special; it is just a connector," he notes, pointing to header bidding as providing a "competitive pathway" to restoring "competing alternatives." This largely mirrors Brinkema's ultimate conclusion.
Given the behavioral remedies now in place, data access could prove valuable, as publishers may gain "a clearer window into how their ad space is really being priced."
Google has long possessed the ability to conceal which prices prevail in ad auctions and what portion of revenue the company retains. Furthermore, Brinkema's orders to encourage alternative exchanges, such as header bidding, could help eliminate the unfair edge held by AdX. The Commission might regard such remedies as adequate to resolve its allegations of self-preferencing by Google.
The Commission operates without a firm deadline, though Ribera has indicated she will examine Brinkema's final ruling closely.
The US judgment does not legally constrain Brussels' options, but it eliminates a crucial point of alignment between the two jurisdictions. The Commission therefore confronts a choice: pursue structural remedies against a business that an American court has deemed too consolidated to separate, or test whether the behavioral remedies imposed in the US can restore competition without divestiture.
