Opt In Robocall Data Base

State/Federal gov't creates a mandatory data base for legal robo-callers to register for a to-be-determined fee. Phone companies would use their technologies to block any unregistered robo-calls from going through to consumers. Any illegally registered robo-callers would be prosecuted to the full extent of the law. Sign up - opt-in fees could be used to fund the program. Obviously, the phone companies would need to cooperate with the government.