This requires cooperation from the telcos at minimum. That's assuming they even keep records of the origination of the call, and not just the (spoofed) incoming

This requires cooperation from the telcos at minimum. That's assuming they even keep records of the origination of the call, and not just the (spoofed) incoming phone number. We really just need to switch our signaling infrastructure because it is just plain insecure. Legislation could make that happen.