Yeah, this is definitely a scam. I got a message left in my voicemail stating "they were gonna file lawsuit against me". But the funny part is that the message started too late, so it never really said who it was that was calling. The message started out as "filing a lawsuit..."  And I think that if IRS is gonna leave a message they would want you to know it was from them!!! And anyways, the IRS doesn't call, they send letter in the mail. And other thing is that the phone number was coming out of the STATE of Washington, not DC. Kinda wish I had answered the phone cause it is sooo much fun to keep them on the phone and play along with them as if you believe them and then end it with some kinda..... "you are an idiot if you think I'm falling for this!!!!" Ha ha ha. But it is a scam and I hope everyone who listens to it knows that and doesn't fall for it, like they want you too