Russian Alexander Vinnik (C) is escorted by police officers as he arrives at a courthouse in Thessaloniki on July 26, 2017. Greek police said that they had arrested a 38-year-old Russian sought by US authorities for allegedly helping criminals launder billions of dollars using Bitcoin. Police said the man, identified as Alexander Vinnik, headed a organisation that has allegedly laundered at least four billion dollars since 2011 using the virtual currency. / AFP PHOTO / SAKIS MITROLIDIS