>Know Your Customer regulations require the company to … know the customer
Which KYC regulations exist for carriers? AFAIK you can walk into any store and get a SIM card. The most they ask for is maybe E911 which they don't check.
Carriers both land/VoIP and wireless must attest to having fraud mitigation measures; this is the "Robocall Mitigation Database" and in Cape's record they exempt themselves from STIR/SHAKEN attestation but state they have measures to prevent fraudulent calling. (which is required for them to be permitted to operate)
What kind of measures are possible to prevent fraudulent calls when the caller is your anonymous customer? The answer is obviously "none," unless you respond to every complaint by terminating service of the offending customer and hoping they don't come back.
Carriers both land/VoIP and wireless must attest to having fraud mitigation measures; this is the "Robocall Mitigation Database" and in Cape's record they exempt themselves from STIR/SHAKEN attestation but state they have measures to prevent fraudulent calling. (which is required for them to be permitted to operate)
What kind of measures are possible to prevent fraudulent calls when the caller is your anonymous customer? The answer is obviously "none," unless you respond to every complaint by terminating service of the offending customer and hoping they don't come back.