Google fights DOJ ad tech breakup as landmark trial opens

TL;DR:

• A U.S. antitrust trial over ad tech opened in Virginia.
  
• DOJ seeks remedies including AdX divestiture.
  
• Google says breakup is unworkable, offers policy fixes.
  
• Publishers will testify about alleged harms.
  
• A ruling could reshape online ads within years.
  

Alphabet’s Google started a critical ad tech antitrust trial in Alexandria, Virginia on September 22, 2025. The Department of Justice and state partners want structural remedies that could force Google to sell parts of its ad tech stack and open its auctions. Reuters reports the DOJ is targeting AdX and pushing open-source measures for auction mechanics, with additional steps if competition does not improve after four years.

What the government wants

The DOJ argues Google runs the tools used by publishers to sell ads and the exchange where ads are auctioned, creating a house-advantage that squeezes rivals and publishers. The proposed remedy includes divesting AdX and potentially Google’s publisher ad server, plus transparency requirements.

Google’s counter

Google says a breakup would inject confusion into advertising markets. It proposes policy commitments instead of divestitures, arguing that modern ad markets are competitive and dynamic.

Why publishers care

Media executives are expected to testify about lower revenue shares and steering that favors Google’s own services. Outcomes could change how revenue flows to newsrooms and creators. 

What happens next

• Bench trial continues through fall 2025.
  
• Judge could order structural or conduct remedies.
  
• Appeals are likely, which means a multi-year path.
  

Why it matters

Online advertising funds the open web. A forced separation of Google’s ad stack would reverberate across publishers, advertisers, and ad-tech competitors and could alter ad prices and transparency.

Sources:

“Google seeks to avoid ad tech breakup as antitrust trial begins,” https://www.reuters.com/legal/litigation/google-seeks-avoid-ad-tech-breakup-antitrust-trial-begins-2025-09-22/, September 22, 2025.