Are you sure this is a problem you want to (try to) solve technically?
- You'll make it very hard for genuine people to contact you.
- You don't solve the problem, you only make it more expensive. As long as the benefit of calling you is bigger than the cost they will jump through whatever hoop to call you.
For some context: this isn't a problem everywhere in the world. In my country there are strict laws about unsolicited phone calls (especially to people who have indicated they wan't to be called[1]). I never get a spam called (automated or otherwise).
Not really personally. The telcos have an interest in making this not a thing, and I have strong hopes that any solution based on this concept would be put out of business by fixing it at that level.
There are laws in the US about this too, with some pretty heavy penalties that are possible to collect in Civil court. The problem is finding the perpetrator, as the phone system makes it difficult to get accurate info on who actually called. I suppose someone could start a class action against the telcos, or an aggressive AG could start a RICO case.
BTW, AT&T, if you don't fix this soon I'm moving to T-Mobile.
- You'll make it very hard for genuine people to contact you.
- You don't solve the problem, you only make it more expensive. As long as the benefit of calling you is bigger than the cost they will jump through whatever hoop to call you.
For some context: this isn't a problem everywhere in the world. In my country there are strict laws about unsolicited phone calls (especially to people who have indicated they wan't to be called[1]). I never get a spam called (automated or otherwise).
[1]: https://www.rijksoverheid.nl/wetten-en-regelingen/productbes...