Thick Indian accent guy, told me to have my wife call him back, "Jack Lewis" at the Treasury department. 213-533-0482 (also the number that shows up on my callerID).
He knew our address.
I asked to tell me my wife's social security number if they are going to start proceedings against me, and he wouldn't answer the question.
I asked to talk to his supervisor to verify the authenticity of his call, so it is not a scam. And he threatened my wife and said "just wait and see what happens tomorrow when the police take my wife away" for tax issues.