A sternly worded, finger-wagging press release.
https://www.fcc.gov/document/fcc-ftc-demand-gateway-providers-cut-covid-19-robocall-scammers
[...]
The FCC’s Enforcement Bureau and FTC’s Bureau of Consumer Protection wrote
to three gateway providers that are facilitating these scam
COVID-19-related robocalls: SIPJoin of Suffolk, Virginia; Connexum of
Orange, California; and VoIP Terminator/BLMarketing of Lake Mary, Florida.
The companies have been identified by the Traceback Group, a consortium
of phone companies that help officials track down suspect calls, managed
by the trade association USTelecom. The Commissions also wrote to
USTelecom to ask its members to begin blocking calls from these providers
if the flood of robocalls is not cut off within 48 hours.