A US judge says Google acted illegally to maintain a monopoly in some online advertising tech, the second time in a year a court found Google acted illegally

The ruling was the second time in a year that a federal court had found that Google had acted illegally to maintain its dominance.

New York Times 2025-04-17 David McCabe

Context & Ripple Effects

The decision follows a 2024 finding that Google illegally monopolized search through default-placement agreements in the search market. Together, the cases extend antitrust scrutiny from how users reach Google to the advertising infrastructure that finances publishers.

The ad-tech ruling is narrower than a blanket finding across the stack: the court distinguished tools used to buy display ads from Google’s ad exchange and publisher-facing ad tools. That distinction will shape the remedies fight and the practical scope of any change.

First-order effects

Google faces a second federal monopoly finding within a year, increasing legal pressure around its ad-tech operations while leaving the display-ad buying-tools finding in Google’s favor.
Publishers and ad-tech customers gain a judicial finding focused on the exchange and publisher-tool layer, strengthening their position in any ensuing remedy process.

Second-order effects

Rival exchanges and publisher ad-serving vendors have a clearer opening to argue for interoperability or other changes that reduce reliance on Google-controlled transaction infrastructure.
Advertisers and publishers will closely watch remedies rather than treat the liability ruling alone as an immediate market redesign; the court’s split finding limits how broadly the case reaches buying tools.

Third-order effects

If remedies alter the links between publisher tools and exchanges, the case could weaken the advantages of vertically integrated ad-tech platforms and make market access more contestable.
Paired with the earlier search ruling, the decision supports a broader judicial willingness to assess digital-market power across distinct layers rather than only at the consumer-facing product level, as two monopoly findings within a year drew attention to.

The trend: US antitrust enforcement is increasingly testing whether platform control across connected digital-market layers can be separated or constrained through remedies.

Discussion

@caseynewton Casey Newton on bluesky
Great news. Breaking up Google's ad monopoly will be good for journalism, publishers, and the web [embedded post]
@timsweeneyepic Tim Sweeney on x
Google was just found in violation of Sherman Antitrust Act sections 1&2 in the ad tech case. The Court found Google illegally tied it ad server and ad exchange.
@jkbustertruster Jonathan Kanter on x
Today is a huge victory for antitrust enforcement, the media industry, and the free and open internet. I am extremely proud of our team at DOJ and partners from the state attorneys general for this momentous victory. Google is now an illegal monopolist twice over.
@jason_kint Jason Kint on x
It all starts with DoubleClick again. Actually, for those paying close attention, it starts with Google's other abusive monopolies (general search and search text ads) being leveraged into dominating all sides of the adtech stack. The two cases “tie” together. Pun intended. /5 [i…
@allthecitizens @allthecitizens on x
And so it begins https://www.theverge.com/...
@hadas_gold Hadas Gold on x
This is big deal though appeals will drag this out for a long time
@lukewgoldstein Luke Goldstein on x
Jonathan Kanter, DOJ antirust chief who brought the Google adtech case, on his massive victory today: [image]
@meadorftc Mark Meador on x
Huge win for @JusticeATR, American consumers and businesses, and our innovation economy. It's also a vindication of what so many of us have been saying for years. Let's keep it up!
@ggreenwald Glenn Greenwald on x
Major loss for Google, and major win for anti-trust law, as federal judge rules that Google is a monopolist in case brought by the Trump DOJ, continued by the Biden DOJ, and now pursued by the new Trump DOJ (same with the current anti-trust suit against Meta):
@khushitavasant @khushitavasant on x
Google's “systemic disregard of the evidentiary rules regarding spoliation of evidence and its misuse of the attorney-client privilege may well be sanctionable,” Brinkema ruled but as Google's been found liable, the court it need not adopt an adverse inference at this juncture. […
@jason_kint Jason Kint on x
whoa! For maybe the third time now, the thing that seems to have kept Google and its chief legal officer from being sanctioned for deleting evidence is that the Court found the entire company to have violated the Sherman Act. That must land hard in Mountain View. /1 [image]
@stockmarketnerd Brad Freeman on x
@theinformation I get why this is positive for $TTD sentiment. Will potentially prevent $GOOGL from owning too many pieces of the supply chain & unfairly routing impressions to its own properties. More fair reporting should be a modest tailwind for $TTD demand based on everything…
@matthewstoller Matt Stoller on x
An Abundance of monopolization by Google
@aripap Ari Paparo on x
Google is an ad tech monopoly! Ruling from Virginia is out. I'm going to 🧵 this as I read it...
@zamaan_qureshi Zamaan Qureshi on x
Google is an illegal monopoly x 2
@aripap Ari Paparo on x
I can't find the ruling or any official press release from the DOJ. So far: ✅ Yes, a monopolist ❌ One aspect was dismissed, but which one!? Likely the accusation that Google Ads has a monopoly, which was the weakest part of the case 🤷‍♂️ No remedies yet? I thought we were
@benremaly Ben Remaly on x
BREAKING: Google illegally maintained monopolies over publisher ad servers and ad exchanges, federal court rules. [image]
@chronotope Aram Zucker-Scharff on x
“The government argued during a three-week trial in September that Google had a monopoly over multiple pieces of technology that are used to conduct these transactions.” https://www.nytimes.com/...
@lutherlowe Luther Lowe on x
Well well well... [image]
@moreperfectus @moreperfectus on x
In a separate case also brought by the DOJ, Judge Amit Mehta ruled last summer that Google violated US antitrust law by maintaining a monopoly in the search and advertising markets. https://www.theverge.com/...
@moreperfectus @moreperfectus on x
U.S. District Court judge Leonie Brinkema just ruled that Google had broken the law to build its dominance over the largely invisible system of technology that places ads across the web. https://www.nytimes.com/...
@aripap Ari Paparo on x
OK I got a copy. Court rejects Google's market definition argument, that all advertising transactions are one big market, and instead finds publisher ad servers are a distinct market: [image]
@_annalanglois Anna Langlois on x
BREAKING: DOJ wins Google ad tech case on publisher ad server market and ad exchange market as well as illegal tying. [image]
@lewis_crofts Lewis Crofts on x
Now the US has gone and done it..... there's nothing holding back @Teresaribera from wrapping up her own case into #Google #adtech. Well, apart from massive EU-US trade tensions and complex questions over the remedy.
@stockmarketnerd Brad Freeman on x
Negative ruling for $GOOGL for anti-competitive practices in online advertising just now per @theinformation. Called their ad business an “illegal monopoly.” This is what $TTD is responding to FYI.
@jason_kint Jason Kint on x
Statement below on the second landmark decision v Google in favor of the United States of America. On a personal note, I'm thrilled. This has been a decade in the making, and I believe history will prove it cost publishers globally more billions than one can count. [image]
@future_of_music @future_of_music on x
Huge implications here for anyone doing business and trying to reach audiences online, which obviously includes music creators, indie labels, venues, arts organzations. Next, the court will consider “remedies” which could include a breakup.
@benremaly Ben Remaly on x
Fmr AAG Jonathan Kanter: “This is a huge victory for antitrust enforcement plain and simple. I am so proud of our team at DOJ for this momentous outcome.”
@_annalanglois Anna Langlois on x
The judge found that websites have difficulty in switching ad servers, but that advertisers don't have the same problem. She said the DOJ did not prove Google monpolized the market for advertiser web ad buying tools, noting the other options they have like social media ads.
@mrddmia @mrddmia on x
This is a huge win for President Trump. Google made its trillion my monopolizing online advertising. Then Google uses its market power to crush competition, shutter small businesses, and crush competition. That's ending. Cheers to @AGPamBondi, @DAGToddBlanche and @AAGSlater.
@sayreevan Evan Swarztrauber on x
Google is twice a monopolist. First it was search, now it's ad tech. [image]
@jimcramer Jim Cramer on x
Google only can take one side of the ad merchandising? BIG
@lukewgoldstein Luke Goldstein on x
turns out it is actually illegal for a bank to also own the New York Stock Exchange which was how a senior Google manager described its control over every stage of the digital ad exchange market [image]
@benbrodydc Ben Brody on x
Interesting that @BasedMikeLee has actually already dropped the reintro of his digital ads breakup bill with the clerk (though I don't believe he's announced it). Feels like this Google decision is great PR for it https://www.congress.gov/...
@matthewstoller Matt Stoller on x
Some extremely nasty words from Judge Brinkema towards Google's lawyers for shredding documents. Says Kent Walker's behavior “may well be sanctionable” but won't do it because Google already lost the case. [image]
@matthewstoller Matt Stoller on x
BOOM: Google loses ANOTHER antitrust suit, it's a monopolist of the software used by publishers to manage online ads, as well as the exchanges used to buy and sell online ads. [image]
@loudmouthjulia Julia Alexander on x
Sometimes, we — and I do mean the collective we — win. It's like imagining what could have happened if antitrust laws existed during the East India Trading Company's reign. [image]
@khushitavasant @khushitavasant on x
BREAKING: In DOJ's adtech monopoly suit v Google, the company is found liable for monopolization of the publisher ad server market, monopolization of the ad exchange market, and unlawful tying of AdX and DFP. DOJ loses claim over monopolization of advertiser ad network market.
@moonalice.com Roger McNamee on bluesky
Meanwhile in what feels like an alternate timeline, Google lost *another* antitrust case. This one relates to adtech and it is really good news. — www.theverge.com/news/650665/ ...
@coricrider.com Cori Crider on bluesky
BREAKING: Google loses the adtech case, has unlawful monopoly over advertising tech. — HUGE deal - it is the source of their monopoly profits - and now puts pressure on the EU to step up and finish the job. — www.theverge.com/news/650665/ ...
@matthewstoller Matt Stoller on bluesky
Google just lost another antitrust case, which means three separate judges have called out different parts of its business as monopolies. Judge Brinkema in this one seriously rolled back Trinko, a very bad decision. — The antitrust revolution marches on. storage.courtlistener.…
@okayy_dan Daniel Hart on x
“We only got away with half the crimes” :)
@rustybrick Barry Schwartz on x
Google says they won half the case :) https://www.seroundtable.com/ ...

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