US court rules Google violated antitrust laws in ad tech market

A US federal court ruled Thursday in favor of the Justice Department in its antitrust case against Google, finding the tech company unlawfully maintained monopoly power in the digital advertising market.

Judge Leonie Brinkema of the US District Court said Google engaged in "a series of anticompetitive practices" for more than a decade to dominate the publisher ad server and ad exchange products. The ruling follows a separate antitrust loss for Google in a search-related case.

"For over a decade, Google has tied its publisher ad server and ad exchange together through contractual policies and technological integration, which enabled the company to establish and protect its monopoly power in these two markets," Brinkema wrote.

"Google further entrenched its monopoly power by imposing anticompetitive policies on its customers and eliminating desirable product features," she added.

She found the company liable under Sections 1 and 2 of the Sherman Act and noted Google's deletion of internal employee messaging unless an employee explicitly turned on "chat history."