PANews reported on March 28 that, according to Cointelegraph, lawyers representing the city of Detroit planned to file an amicus brief in Coinbase's lawsuit against Michigan. Judge Shalina Kumar of the Eastern District of Michigan granted the amicus brief filed by the Detroit lawyers, supporting the Michigan authorities' motion for a preliminary injunction. The deadline for filing was April 3.

Last December, Coinbase filed lawsuits against gambling regulators in Michigan, Connecticut, and Illinois to clear obstacles for launching its prediction market service. The company argued that prediction markets fall under the jurisdiction of the Commodity Futures Trading Commission (CFTC), not state gambling regulators.