Phase 1 of blocking robo calls goes live in Canada today
The CBC did a good job of explaining the phases and restrictions. In a nutshell, as of December 19, 2019, Telco in Canada must either block invalid caller ID numbers (e.g. ones that are not dialable), or, provide the user some filtering options.
Now, this will be unlikely to make much difference. The spammers just spoof the caller ID to be a real number to get around this. What we really need is BCP38, a tool from the IP world where I accept a packet from your only if the source IP is one I would route back to you.
There is another phase coming, a sort of verification of networks approach, somewhat along the lines of BCP38, that comes online by Sept 30, 2020. Will that stop them? No. The only thing that will stop the scammers is destroying the risk:reward ratio. We must increase their risk (getting arrested, fined, going to jail, etc), and lower their reward (less people fall for the scam).
On the first, this is an enforcement issue. On the second, its an education issue as much as a technology one. If you each explain to a few friends that "no one takes payment in Apple iTunes cards" and some of the other common features of the scam, and if those friends explain to a few, this inoculates the population. Herd immunity.
I suppose we could also introduce a system where every phone call was a callback: you call me, my phone sees your caller ID, and calls you back. This would guarantee the system, and make the enforcement much simpler (but still not perfect).
As for a better sort of punishment for those caught, how about we develop a method to surgically implant taste-buds in their sphincter's? Who's with me on that!