I have caller id on both my phone lines, I never answer a number I do not know, if they want me for something they can leave a message, most never do. I did find the setting on my I phone to send all unknown numbers to voice mail without ringing. That is great but if I am expecting a call from say a Dr's office where they may call on a separate number than the main one for the clinic, I may miss it and have to pick up message on voice mail. yep, the spoofing is a real pain. When they used to have a real person on the end, I would sometimes just set the phone down with the caller still talking away and walk away. One time, I came back and the person was still talking. Oh Well!