U.S. citizen Virgil Griffith has been arrested for travelling to North Korea and providing courses on blockchain technology and cryptocurrency use in violation of international restrictions. FBI Assistant Commissioner William F. Sweeney Jr. issued a statement about Griffith's arrest: Griffith traveled to North Korea without federal permission, and he knew he was breaking the law. Griffith allegedly traveled to North Korea in April last year to participate in and speak at the Pyongyang Blockchain and Cryptocurrency Conference. He also chose to provide North Korea and its participants with information and products that could be used against the United States and its allies. The Ethereum Foundation issued a statement saying that Virgil Griffith's decision to travel to North Korea was purely personal.