Left a recording saying that the IRS is filing a lawsuit against me. My CPA said it's a scam. I never called the number back... But it was scary at first however I trust my CPA and he said the IRS will never call you... They would send you cerified mail.
So, after receiving my second "IRS is filing lawsuits (plural!) against you" voice message this morning, I decided to call them back, fully aware it is a fraud. The first time "Officer Smith" of the IRS answered the phone in a thick Indian accent with lots of call center noise in the background. I asked for his name and he said Robert Smith. I asked for his Manager's name and he hung up on me. I called right back and got the same Officer Smith. He asked if I had a pen and paper handy to write down some important information. Playing along, trying to gather some actionable information, I told him I was ready. He then said "[***] YOU" in good, clear English and hung up. Who is spending money to support such crap?
When I called them back and asked for a name, they gave me the name James Watson. I told "Mr. Watson" what a lovely Indian accent he has and he got furious. Then I blew my whistle as loud as I could into the phone. Then he hung up. Have a little fun with them. :-)
The good news is that the whole whistle/air horn thing will damage hearing. The bad news is that it will be your hearing that is damaged. That whistle/air horn thing is an urban myth.