Meta suffered a major defeat on Wednesday that could severely undercut its Facebook and Instagram advertising business after European Union regulators found it had illegally forced users to effectively accept personalized ads.The ruling is one of the most consequential judgments since the 27-nation bloc, home to roughly 450 million people, enacted a landmark data-privacy law aimed at restricting the ability of Facebook and other companies from collecting information about users without their prior consent.The judgment puts 5 to 7 percent of Meta’s overall advertising revenue at risk, according to Dan Ives, an analyst at Wedbush Securities.judgment is the latest business headwind facing Meta, which was already grappling with a major drop in advertising revenue because of a change made by Apple in 2021 that gave iPhone users the ability to choose whether advertisers could track them.Meta said last year that Apple’s changes would cost it about $10 billion in 2022, with consumer surveys suggesting that a clear majority of users have blocked tracking."