On December 123rd, under the name of "marketing, promotion and finding customers", lists of sensitive information about participants in cryptocurrency industry events have been illegally sold, becoming a treasure trove of data coveted by scammers and malicious actors. The lists detail participants' full names, phone numbers, nationalities, job titles, companies to which they belong, as well as personal and business social media links, which are often collected during the event registration process at conferences or breakout venues. Cointelegraph obtained a "sample" of the list from a seller via Telegram, including four lists from different events, each with about 60 to 100 participants and containing different data points. The events mostly took place in the fall of 2024, and the participants came from multiple countries such as South East Asia and India. This suggests that there is an organized international blockchain event participant data transaction. These lists are just the tip of the iceberg, and the seller also shared other sample images associated with Blockchain Fest and Devcon.