Message was left that IRS is filing a lawsuit. Clearly fraudulent because you would get a letter, especially if there were any discrepancies, prior to any lawsuit. The bigger question is who is going to go after these people to shut them down? There are people out there that might fall for this and loose a lot of money in the midst of the scam.
This is a scam trying to scare people into giving money by saying they are the "IRS" and are filing a lawsuit against you. The is bogus; the genuine IRS would never contact you this way. Just delete the message.
Caller leaves message that the IRS is filing a lawsuit against me and instructs me to call the number. Pure scam. The IRS does not phone and leave messages. They communicate via snail mail.