Confidential information about international athletes surfaced on the Internet Wednesday -- the second such exposure this week. Russian hackers allegedly stole from the World Anti-Doping Agency confidential data on medical drug exemptions given to 25 athletes from eight countries. Information about four athletes appeared online earlier in the week. A group of Russian hackers used phishing techniques to compromise the credentials of the athlete who blew the whistle on a state-sponsored doping scheme in Russia, WADA said.