On February 4, 2020, the Enforcement Bureau of the FCC sent a letter to seven U.S.-based voice service providers identified by the USTelecom Industry Traceback Group as likely gateways through which illegal robocalls originating in foreign countries are connected to the U.S. telephone network. The letters mention the Traceback NPRM (discussed above) and encourage the companies to join these efforts to trace and prevent unlawful traffic originating outside of the U.S.  The letters also request that, by February 17, 2020, each company respond to numerous questions about specific preventative and responsive actions they have taken and their business relationships with foreign clients/callers.