Federal prosecutors in Detroit have seized about $12 million in cash they allege was part of a massive money laundering operation, called “The Shadow Exchange,” operating between the U.S. and the United Arab Emirates. A forfeiture complaint unsealed Thursday in federal court in Detroit alleges that some of the laundered money was used to buy armored vehicles for an illegal drug trafficking operation based in Michigan. The shell companies involved in the scheme, mostly located in Dubai in the United Arab