Had a msg on my home phone...very thick accent and could hardly understand BUT I did get some sort of tax litigation and attorney.  Called the number lady left me 415 690 1302 and nothing but spanish.  this number 415 690 1322 was on my caller ID but it always goes straight to busy.  Left a msg with the TRUE IRS about this.

Got a call from this number AND from 415 251 6327, each with the same exact message except the call back number is the respective number called from.
Very annoying loud beep starts the call with an indistinguishable part of a deep man's voice, then the message starts from a woman with a very thick accent (my guess is India).
Some excerpts:
"tax litigation department" (of what???)
"extremely time sensitive"
"the very second you receive this message"
"you or your recent attorney of record"
"before any legal action takes place"
"deficiency in your income tax"
"hard line" (for returning the call)
"don't try to disregard this message"
"reference number"