A federal court found Google monopolized two ad-tech markets

The revenue mechanism

On 17 April 2025, Judge Leonie Brinkema of the US District Court for the Eastern District of Virginia issued a 115-page memorandum opinion in an antitrust case the federal government and seventeen states brought against Google's advertising-technology business. The mechanism at issue is the publisher-side stack deciding which ad fills a given impression and clears the resulting sale: a publisher's ad server, Google's is called DFP, selects among demand sources, and an ad exchange, Google's is AdX, runs the auction connecting that demand to advertiser bidding tools. Plaintiffs argued Google used its position in both pieces to entrench its own products at the expense of publishers' ability to route inventory to whichever ad server or exchange offered the best terms.

What the documents show

The opinion states plainly that, after a three-week bench trial, the court found plaintiffs 'failed to prove that there is a relevant market for open-web display advertiser ad networks', but 'have proven that Google has violated Section 2 of the Sherman Act by willfully acquiring and maintaining monopoly power in the open-web display publisher ad server market and the open-web display ad exchange market', and separately found Google 'unlawfully tied' its publisher ad server and ad exchange together, violating both Section 1 and Section 2 of the Sherman Act. The opinion is explicit that liability and remedy are separate steps: having found Google liable, the court said it 'will set a briefing schedule and hearing date to determine the appropriate remedies'. A Department of Justice press release, retrieved 16 September 2026, confirms a further remedies ruling in this case followed, ordering integration and data-sharing obligations, though that later ruling is a distinct proceeding from the liability finding described here.

The assumptions exposed

A liability finding under Section 2 does not itself state a dollar figure, a divestiture, or any other remedy; those are decided in a later phase, and a reader could easily over-read the April 2025 ruling as having already restructured Google's ad-tech business, which it had not. The court also narrowed the case: the advertiser ad network market claim was rejected for lack of proof, a distinction that matters because the ruling does not establish monopoly power in every ad-tech market plaintiffs alleged, only the publisher ad server and exchange markets plus the tying claim.

What to check before you rely on it

A publisher assessing this ruling should separate the liability finding from whatever remedy a later order actually imposed, since the two were decided more than a year apart. This is an editorial checklist, not legal advice.

• Am I citing the April 2025 liability finding, a later remedies order, or conflating the two?
• Which market, publisher ad serving, ad exchange, or advertiser ad networks, does the claim I am reading concern?
• Has the ruling I am relying on been affected by an appeal since it was issued?

The opinion is a primary legal record of what one court found about two ad-tech markets on one date; it is not, by itself, a statement of what changes in Google's products.