Got a voicemail from "IRS" telling me this is their final notice and they will bring a lawsuit against me. Only said to call them back for more information. Seemed bogus, feel better that others have posted about this scam!
Glad you checked here and didn't fall for it. Here's some info on the scam from the real IRS and some news feeds.
https://www.irs.gov/uac/newsroom/irs-repeats-warning-about-phone-scams
http://www.forbes.com/sites/johnwasik/2016/06 ... u/#6cb8a18e171f
https://www.pindropsecurity.com/irs-phone-scam-live-call_analysis/
http://money.cnn.com/2016/05/25/news/irs-impersonators-scam/