The ruling paves the way for a second trial to determine potential fixes, possibly including a breakup of Alphabet, that would change the landscape of the online advertising world that Google has dominated for years.
It is also a green light to aggressive U.S. antitrust enforcers prosecuting Big Tech, which faces criticism from across the political spectrum.
"The court reaches the following conclusion: Google is a monopolist, and it has acted as one to maintain its monopoly," District Judge Amit Mehta wrote. The search engine giant controls about 90% of the online search market, and 95% on smartphones.
The “remedy” phase could be lengthy, followed by potential appeals to the D.C. Circuit and U.S. Supreme Court. The legal wrangling could play out into next year, or even 2026.