This is relatively new to me and I just got called... nobody on the other end.
My dear departed aunt, she was a school teacher and my uncle was a police detective, so their number was unlisted. Yet they got all sorts of callls with heavy breathing, etc. My aunt kept on the kitchen counter, a police whistle and a pair of ear muffs, the real ones made for industry. Well, she'd hear some 'hole on the other end, put down the phone, put on the hearing protector and blow the whistle into the phone full blast. She didn't get another call.
Just received a call from this number and did not answer. Went to this site and see what the call was about. Will block the number and hope they stop as I am disabled and cannot get to the phone in a timely manner sometimes if I have left in another room. So glad some of you have reported them! Sick to death of these scammers! Get a JOB!