I want the phone to block made up numbers. There is a North American Numbering Plan that defines the ranges of valid numbers. I should not be able to receive an incoming call from any number that is not part of the numbering plan.

I don't think that would work too well. I have actually received a call from my own cell phone...on my cell phone. Now that I think about it I should have answered it to see if it was someone or if it was busy. Either way this is getting out of hand.

It could be one prong on the fork that stops robocalls. It sure doesn't solve everything. There is no silver bullet that just stops all robocalls, its going to take a multi-faceted approach.

That's not really a solution when the scammers are either picking random VOIP numbers out of a hat or spoofing them.

Spoofing aside (that's a telecom problem, and it obviously needs fining and fixing), if enough VOIP-owned numbers get blocked, the services running those numbers will raise prices and/or step up their banning game. It's not a sure-fire fix, totally agreed, but I don't see how it'd make the situation worse.

It would be nice to be able to reject a call and have the option to just cut it off instead of sending it to voicemail.

Do they call you from consistent numbers? Every time I get a robocall it seems to be from a new number

If the first 8 digits are identical to my own, mark as spam. We can do it in mail, why not in phone.