Main culprits in this nonsense are the phone companies who profit off it at their customers' expense. It's basically like cable tv where you're expected to pay to watch commercials.
When you order a phone line, should the Phone Company put you through a detailed and exhaustive screening process mandated by their lawyers because they've been sued for the contents of calls that some of their customers have made? Should they then be allowed to monitor your calls for violations of their AUP? I mean, if they're responsible for the content of your calls then they need to be able to monitor them, right?
No, I completely disagree with you. Phone Companies aren't responsible for how their communication channels are abused any more than road builders are responsible for the getaway of bank robbers who use roads.
Cable Companies' are a little different. Mainly because they tend to be the carrier of the content, the creator of the content, and the beneficiary of both. This wouldn't be so bad if it weren't for the fact that in many areas they have a government-enforced monopoly on the biggest data pipe into our homes.
I don't think it's beyond the pale to suggest that phone companies don't allow scammers on their network. Look what happens to ISPs who allow spambots. And there's no policing of content required, merely responding to valid third party reports.
For starters they could let you block calls from unknown numbers.
Indeed, they could require some sort of licensing for numbers/entities originating large volumes of calls.
They could also disallow caller id blocking.
But the reality is abusive telemarketing tactics are a substantial revenue stream for them, so they dont give a shit.
The phone company doesn't need to police anything -- they just need to identify the endpoints of a call when a subpoena is issued.
The real issue is that phones were ever allowed to ring in the first place. They should all just leave a message which should then be stored until a I chose to listen to it. Then in the future, calls from that number could be allowed.
In addition the phone company could allow you to preunblock certain numbers, such as those from your schools and hospitals.