A Russian national who founded a cryptocurrency exchange that the justice department says became a haven for the proceeds of criminal activity has been arrested, federal officials said on Wednesday. Anatoly Legkodymov, who lives in China, was arrested on Tuesday night in Miami and was due in court on a charge of conducting an unlicensed money-transmitting business. Prosecutors allege that Legkodymov’s cryptocurrency exchange, Bitzlato Ltd, of which he served as majority owner, did not implement required anti-money laundering safeguards and required only minimal identification from its users, even permitting them to supply information belonging to “straw man registrants”, people serving…