The Spanish financial regulator CNMV has imposed a 5 million euro fine on X, formerly known as Twitter, for failing to verify the legality of a cryptocurrency advertising campaign. The social media platform allowed ads for Quantum AI, an unauthorized entity, without checking if the company was on a regulatory blacklist. This action violates Spain's financial advertising law enacted in March 2023. The investigation, initiated in November 2023, revealed that X did not ensure the advertiser possessed the necessary licenses to offer investment services. This case highlights the increasing regulatory pressure on digital platforms to monitor crypto-related content and prevent fraudulent promotions.