As the courtroom drama in Alexandria, Virginia, enters its final act, Alphabet Inc.’s Google finds itself defending the heart of its advertising empire against U.S. antitrust enforcers. The trial, which began in September 2024, has now reached the remedies phase, where the Department of Justice (DOJ) is pushing for structural changes that could reshape the digital advertising market. At stake is Google’s dominance in ad technology, accused of stifling competition through practices like tying its tools together and favoring its own platforms.

Judge Leonie Brinkema, presiding over the case, ruled in April that Google had unlawfully monopolized key parts of the ad tech stack, including display ad servers and exchanges. However, the DOJ’s claim that Google dominated ad networks fell short. Now, in this remedies hearing set to conclude by late September 2025, the government is advocating for a breakup, specifically the divestiture of Google’s Android operating system or parts of its ad tech business, to prevent what it calls an anticompetitive stranglehold.

The DOJ’s Aggressive Push for Divestiture and Its Potential Ripple Effects on the Industry

Prosecutors argue that only a forced sale of Google’s ad manager or related assets can restore fair play, pointing to internal documents revealed during the trial that show Google’s executives discussing ways to lock in publishers and advertisers. Witnesses, including economists and former Google employees, have testified to the barriers rivals face, such as The Trade Desk or smaller players struggling against Google’s integrated ecosystem. According to reporting from Digiday, the DOJ’s timeline includes wrapping arguments by September 25, with a potential ruling by year’s end that could mandate data-sharing obligations or bans on exclusive deals.

Google, in its defense, contends that such remedies are overreaching and could harm innovation. The company’s lawyers have proposed behavioral fixes, like opening up its ad exchange to more competition without a full breakup, arguing that the market has evolved rapidly with AI-driven tools. Executives like Philipp Schindler, Google’s chief business officer, are expected to take the stand to emphasize how divestiture might disrupt services for millions of publishers and advertisers reliant on Google’s infrastructure.

Key Witnesses and Arguments Shaping the Trial’s Outcome

The remedies phase has featured a parade of expert witnesses, with the DOJ calling on antitrust scholars to model post-breakup scenarios, while Google counters with economists highlighting the futility of splitting assets in a fast-moving tech sector. As detailed in Digiday‘s analysis from March, critics question whether a divestiture would even matter given emerging technologies like generative AI that could render current ad tech obsolete.

Industry observers are watching closely, as a breakup could open doors for competitors but also introduce uncertainty. For instance, if Google is forced to sell its ad server, buyers like private equity firms or tech giants such as Microsoft might step in, potentially consolidating power elsewhere. The trial’s closing arguments, scheduled for this week, will pit these visions against each other, with Brinkema’s decision likely to influence ongoing antitrust scrutiny of Big Tech.

Broader Implications for Digital Advertising and Regulatory Precedents

Beyond the courtroom, the case echoes Google’s recent search antitrust loss, where a judge opted against divestitures but imposed data-sharing rules. Sources from Digiday note that ad executives are preparing for scenarios ranging from minimal changes to a fragmented market, where publishers might gain leverage in negotiations.

As the hearing nears its end, the outcome could set a precedent for how governments tackle tech monopolies. If the DOJ prevails, it might embolden actions against other platforms, fostering a more competitive environment. Yet, Google’s appeals process could drag on for years, leaving the ad world’s future in limbo. For now, all eyes are on Brinkema’s gavel, which may redefine the rules of digital commerce.