Call blocker might be of some help. Also don't pick up on numbers you do not recognize, or where there are caller IDs that seem odd. Or where there is no caller ID. There’s no way to stop the calls from being initiated. Calls originate in India and Pakistan. They spoof local numbers.
Got this cell call this morning and let it go to voice-mail. IRS scam (case # CF79591 - Google it). All the info you need is here at this other 800Note link: http://800notes.com/Phone.aspx/1-202-741-4061
Received a call from this number, I don't answer the phone if I don't recognize the number so it went to the answering machine. It was a computerized voice and said I needed to call regarding a criminal lawsuit. I knew it was a scam because at the end it said "if you do not call back I do not wish you a good life as this unfolds on you." Obviously a scam.
I received this call from the DC area. It was a computerized voice stating it was from the IRS concerning a lawsuit. I called the number back and it would not connect. Looked the number up and I ended up here on this site. This smells of Scam and not protocol for this Govt agency.