Russian Sports Minister Vitaly Mutko has challenged the World Anti-Doping Agency to "prove that hackers from his country were responsible for the leak of records relating to some of the biggest names in American sport," according to Owen Gibson of the London GUARDIAN. A group called Fancy Bears published confidential data relating to the Williams sisters and U.S. gymnast Simone Biles, "including details of banned substances for which they had a therapeutic use exemption." Mutko said, "How can you prove that the hackers are Russian? You blame Russia for everything, it is very in fashion now. We are also concerned because they have the same data of the Russian athletes and we can also be a victim, it doesn’t matter which athlete." Mutko "resolutely rejected any suggestion that the Russian state was involved in the hack," which left 10,000 WADA records "potentially compromised." He said, "All the information must be protected. Those are personal data." WADA President Craig Reedie said that it had "pretty authoritative information" that the hackers had close connections to Russia. Reedie: "They have been attacking our system -- we have been under attack for weeks. It is an attack on the system, the anti-doping system" (GUARDIAN, 9/14).