OMG!! I hate the private caller thing. I get it DAILY. Sometimes several times. NEVER a message. WTH?
I am considering getting the call screening service due to the absurd amount of private callers and 1-866 numbers that are obvious telemarketers. I don't answer them, then they never give up and keep calling, and calling, and calling.
With call screening, the caller gets a recording saying calls to my number are screened. They MUST record their voice explaining who it is calling. You can override this for numbers you know, thus not driving schools, work, friends, family absolutely crazy. But then it forces the person to do this. If they don't, they don't even make it to my answering machine. I can pick up the phone WHILE they are recording who they are to identify themselves, and the caller isn't aware if I'm listening or not. If I want to answer, I can, or I can let the machine take it.