A US federal judge has ruled that Google has been illegally monopolising the online advertising technology market. The court found Google liable for 'wilfully acquiring and maintaining monopoly power' in the publisher ad servers and ad exchange markets. This ruling potentially forces Google to sell off key parts of its ad business, including Google Ad Manager. Google faces another trial regarding its alleged search dominance, increasing the pressure for significant business practice changes. Google plans to appeal the decision, but this ruling marks a substantial setback, potentially reshaping the digital advertising landscape and impacting Google's market position.