A friend has a lot of fun calling people and using altered caller ID. I am not a prankster and stayed below his radar for quite a while. Lately he calls me at inconvenient times and it looks like my wife called. The call is garbled and I usually walk out of the building to call my wife who may also be in a meeting and has to walk out to talk to me. We then decide it was a prankster and go on about the day. I would like to know if there is some way to officially let him know he is on dangerous ground, without causing him trouble beyond belief. Perhaps his carrier would warn him or mine would. Can I block him from calling me when he uses a spoofed number? Please advice. Thanks.