The U.K.'s Financial Conduct Authority has warned cryptocurrency firms in the country to shut down their ATM machines, according to a statement Friday. None of the 27 digital asset firms registered with the FCA have been approved to offer crypto ATM services, the agency noted. This implies "any of them operating in the UK are doing so illegally and consumers should not be using them." If crypto firms that operate these ATMs don't comply with the FCA, they could face enforcement action. On Dec. 29, U.S.-based Santo Blockchain Labs bought 50 Bitcoin ATM machines.