Got scary email with this number

Received a call from this number and didn't answer.  I listened to the voicemail about "failure to appear in front of a magistrate judge."  I decided to call them back.  I asked the woman on the other end "Who is the magistrate judge that I failed to appear in front of?"  She hung up on me.  I called back several times inquiring who they were representing and to STOP SCAMMING AND THREATENING PEOPLE!!!  I also informed her after several instances of her hanging up on me, I will find her location and "appear at her doorstep with a few of my military buddies to straighten my so called 'federal criminal offense' out.

Received the same call.  The good luck part was creative.  Most people know that some federal issue is not going to be from a robo call.