I'm in the UK and many years ago I was working for a US company over here. (This happened in 2000 so my memory isn't 100% on it) One of my managers asked me t

I'm in the UK and many years ago I was working for a US company over here. (This happened in 2000 so my memory isn't 100% on it) One of my managers asked me to call him at home (either in the US or Canada) and when I dialled, I was hit with a message along the lines of "I do not accept unsolicited calls" before I got through to him. Now, this is the hazy bit, I am sure it asked me to press a key to continue. Assuming I'm not talking nonsense here, how hard would it be to have a service like that where the message asks you to type in a number it reads out in order to continue: It would wipe out the current generation of robocalls immediately. Like popups and tracking blockers, it would obviously start an arms race but it would at least be a start.