Got a call from the same phone number with the following message
I am calling you from Legal Affairs at the US Treasury Department. My batch number is IRN9165. The nature and purpose of this call is regarding an enforcement action which has been executed by the US Treasury Department regarding tax fraud against your name. Ignoring this would be an intentional attempt to avoid initial appearance before the magistrate judge or exempt jury for a federal criminal offense. So before this matter goes to federal claim court house or before you get arrested, kindly call us back at our number as soon as possible. Our number is (415) 493-0733. Hope to hear from you soon before charges are pressed against you. Thank you.
It is a scam, but I can see how so many would fall for this out of fear that they might have done something wrong.. it is sick!