Callers are hardcore Indian or Pakistani scammer/extortionists. As such they are beyond the reach of US law.
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.
I got this call this morning stating he was from the IRS tax audit department of the Internal Revenue service . Stating
The very second you receive this message yoiu need to leave your work aside and dial a number. the number is 214 935-8751. I repeat the number is 214+935-8751 now if you don't return the call or in case if I don't hear from your attorney either the only other this what I can do is wish you a happy life as the law enforcement team of you state will be soon at your doorstep Goodbye
I got that same message twice yesterday same threatening call.He was from the RIS and that the three police would be at my door and he and if I didn't return the car all he could do was wish me a happy life.