Comment by pavel_lishin

I genuinely don't think this is one of those problems that you can solve with technology. As long as America, and the world, uses a fairly short number for telephone calls - which it must - people will be able to either dial whole exchanges for effectively nickels, or they'll be able to buy or steal (or both) this information.

This feels like a problem that can only be solved with regulation, the kind with some muscle behind it. The kind that becomes an existential threat to the sort of company that allows someone to call me five times a day to sell me a home security system with a robot lady, who then redirects me to a human in a boiler room in Tashkent/Dhaka/Indianapolis/Sevastopol/Mumbai.