The Federal Communications Commission (FCC) has moved to fine Voxbeam Telecommunications $4.5 million, bringing renewed attention to how foreign call traffic is still being used to push bank impersonation scams into the U.S. telecom system. The Voxbeam robocall case stems from an FCC investigation that found the company allegedly routed suspicious robocalls onto American networks, calls that, under existing rules, should have been blocked before reaching consumers.

At the center of the Voxbeam robocall case is a compliance failure that regulators consider fundamental. U.S. voice providers are barred from accepting traffic from operators not listed in the FCC’s Robocall Mitigation Database (...