The U.S. Department of Justice formally asked a federal court to compel Google to sell major parts of its advertising technology operations, following a judge’s determination that the company illegally monopolized key segments of the online ad market. In a court filing dated May 5, the government outlined its proposed remedy, arguing that structural changes are necessary to address the competitive harms caused by Google’s actions.
Google, in its own court filing, countered that divestiture is unwarranted and technically impractical, proposing alternative conduct-based remedies instead. The dispute now heads towards a remedies trial scheduled for September 22, 2025, presided over by U.S. District Judge Leonie M. Brinkema in Virginia.
Judge Brinkema’s April 17 ruling found Google liable for unlawfully maintaining monopolies in the markets for publisher ad servers and the ad-exchange market, and for illegally tying the two products together (its DoubleClick for Publishers, or DFP, ad server, now part of Google Ad Manager, and its AdX ad exchange, a real-time marketplace). The government argues that only breaking up these businesses can effectively restore competition.
DOJ Details Proposed Divestiture Plan
The government’s proposed remedy, detailed during a May 2 hearing and in court filings, involves several steps. It calls for the complete sale of Google’s AdX ad exchange under court supervision, with the DOJ approving the buyer. Furthermore, the government wants Google banned from operating an ad exchange for ten years following the divestiture.
For the DFP publisher ad server, the DOJ suggests a phased approach: first, forcing Google to grant competitors real-time access to AdX bidding data via Prebid (an open-source header bidding technology allowing publishers to solicit bids from multiple ad exchanges) and requiring Google to open-source DFP’s auction logic.
Subsequently, the DOJ wants the full divestiture of the DFP suite. Underscoring the government’s position at the May 2 hearing, DOJ lawyer Julia Tarver Wood stated, “To leave Google with ‘90 percent of publishers beholden to them is, frankly, too dangerous.’” The government has reportedly labeled Google a “recidivist monopolist,” arguing behavioral fixes are insufficient. As a further measure, the DOJ suggested Google place 50% of AdX and DFP net revenues into escrow until the sales are complete, potentially funding publisher switching costs.
Google Argues Breakup is Unworkable and Harmful
Google maintains that such a drastic structural remedy is unnecessary and unfeasible. “The DOJ’s additional proposals to force a divestiture of our ad tech tools go well beyond the Court’s findings, have no basis in law, and would harm publishers and advertisers,” stated Google VP of Regulatory Affairs, Lee-Anne Mulholland.
Representing Google at the May 2 hearing, lawyer Karen Dunn asserted that a breakup lacks legal precedent and is “very likely completely impossible” technically. Dunn argued that separating the deeply integrated technologies could undermine user privacy and security, and questioned who could realistically buy the complex technology besides other tech giants.
Instead, Google proposes conduct remedies, including granting real-time AdX data access via Prebid and eliminating its Unified Pricing Rules (UPR) for open web display ads. Google also committed to never reintroducing first-look or last-look advantages in its open web auctions. During the May 2 hearing, Judge Brinkema reportedly appeared skeptical about the necessity of selling DFP, questioning if divesting AdX combined with data-sharing requirements might be sufficient.
Broader Antitrust Scrutiny and Alleged Patterns
This ad tech case is one of two major antitrust battles the DOJ is currently waging against Google. The other, focused on Google’s search dominance, is also in its remedies phase before Judge Amit P. Mehta in Washington D.C., where the DOJ seeks remedies including the possible forced sale of the Chrome browser. Google’s counsel John Schmidtlein called that demand “extreme” and “fundamentally flawed” during the search remedies trial that began in April.
The Justice Department explicitly links the two cases, alleging a pattern where Google leverages its existing market power. Government lawyers in the search trial highlighted Google’s deals to pay for default placements, pointing to a January 2025 agreement involving “enormous sums of money” paid monthly to Samsung for Gemini AI preinstallation, as evidence of tactics similar to those found illegal in search being applied to the AI market. “We’re here to restore competition to these markets,” DOJ lawyer David Dahlquist stated in the search trial, adding, “The antitrust laws are designed to adapt to advances in technology, the oil companies and railroads of yesterday are the internet and search engines of today.”
The outcomes of both remedy proceedings, expected later this year and into 2026, hold the potential to reshape Google’s business significantly.
