Google’s antitrust woes are continuing to mount, just as the company tries to brace for a future dominated by artificial intelligence.

On Thursday, a federal judge ruled that Google held illegal monopolies in online advertising markets due to its position between ad buyers and sellers.

The ruling, which followed a September trial in Alexandria, Virginia, represents a second major antitrust blow for Google in under a year. In August, a judge determined the company has held a monopoly in its core market of internet search, the most-significant antitrust ruling in the tech industry since the case against Microsoft more than 20 years ago. 

Google is in a particularly precarious spot as it tries to simultaneously defend its primary business in court while fending off an onslaught of new competition due to the emergence of generative AI, most notably OpenAI’s ChatGPT, which offers users alternative ways to search for information. Revenue growth has cooled in recent years, and Google also now faces the added potential of a slowdown in ad spending due to economic concerns from President Donald Trump’s sweeping new tariffs.