“I’ve taken it a step further. If it doesn’t return an ID from my contact list, it goes unanswered. If they leave a V-mail I’ll listen. Most don’t.”
When they don’t, I block the number.
Sometimes that doesn't work. I've blocked over a half dozen numbers which called offering a free health screening in association with my insurance plan. The calls came from area codes associated with Maryland, Georgia, Florida and Texas. All with the identical message being left in my voice mail.
I finally answered one that gave me the option to press #2 to receive no more calls from them and it worked......LOL!