Manori Ravindran International EditorA cryptocurrency Ponzi scheme that pulled in an estimated $4 billion worldwide is getting the documentary treatment.Sky Germany, the U.K.’s Channel 4 and super-indie Fremantle are backing a three-part doc series about the con, which was spearheaded by the mysterious Dr. Ruja Ignatova, who is still on the run from law enforcement officials.“Crypto Queen” (working title) promises to shed exclusive new light on one of the biggest digital scams of the last decade.