A protester supporting Edward Snowden, a former contractor at the National Security Agency (NSA), holds a placard depicting U.S. President Barack Obama during a demonstration in Hong Kong June 15, 2013. FBI Director Robert Mueller said on Thursday that authorities would move aggressively to track down Snowden and hold him accountable for leaking the details of extensive and top-secret U.S. surveillance efforts. REUTERS/Bobby Yip (CHINA - Tags: LAW POLITICS SCIENCE TECHNOLOGY) Published: Čer. 15, 2013, 10:21 dop. | Foto: Reuters