I don't know if you've ever tried to report a nuisance call, but, as the article hints at, there's a wall of apathy at the phone company and law enforcement end

I don't know if you've ever tried to report a nuisance call, but, as the article hints at, there's a wall of apathy at the phone company and law enforcement end to overcome. If they go the extra step to look up ANI, well, that is spoofable as well. Do they regularly go further than that? Making it not so trivial to spoof caller ID would reduce abuse just like some ISPs have elected to implement egress filtering. Just because the service is currently wildly untrustworthy doesn't mean that it should be or is required to be. There IS a market for better authentication and filtration of nuisances that companies like Google seem to be aware of.