I was getting literally ten calls a day from "Anonymous." They did have a phone number, so I was able to block them individually from my phone. New ones came each day though from different numbers. I was looking at Comcast's website the other day and saw that under their call blocking feature that you can check a box to block all anonymous calls. I did that, and they have stopped.
That was such an annoyance. I thought some of you might be able to use this information.
The Bluebird Carries The Sky On His Back"
-Henry David Thoreau