Received a call with automated message claiming the IRS was going to file a lawsuit if I didn't call them at this number immediately. I purposely called from a different number. No answer and straight to a busy signal. Clearly a con as no IRS number would default to a busy signal.
Definitely a scam. I received this voicemail two days in a row now (1st one on Jan 6th, then another the following day). It was a robotic female voice saying that I am being sued by the IRS.
The IRS website says that you can report these calls at www.tigta.gov or 1.800.366.4484.