Found this number on my caller id.

IRS scammer saying I was the target of a lawsuit by the IRS and to contact them at this number. Came across as Cell Phone CA and I let it go to the answering machine as I did NOT recognize the number. Filed complaint with the IRS as a scam attempt.

Obviously this is a scam.  Unlike most scam or robocalls this one actually left a voicemail.  It was a recorded message about how I was in big trouble with IRS and they were suing me.  I had to call this number to stop the lawsuit.  I assume that if I called they would eventually phish out some goodies like my SS number, bank account or credit card info, and proceed to steal my money or identity or both.  Giveaways that this is a scam: 1 - I don't owe IRS anything; 2 - If IRS wanted anything from me they would have contacted me (by mail) long before any "lawsuit" happened; 3 - IRS phone number would be in DC (Area Code 202), maybe Maryland (301 or 410), possibly VA (703) -- NOT California (310).  These crooks are stupid.  Sadly they will probably find stupider people to scam.

These freaks called twice and when I confronted them about their scam he called me an MF and hung up.  I called back - they played dumb.  It's an IRS scam group in LA (all males, all asian accents).