I got the same call, a recording claiming to be the IRS. They called 2x today, once at 1:30 p.m., once at 5:30 p.m.  I figured it was a scam.

This is a well known scam.  The IRS does not call you & threaten lawsuits.

Got the same call

Internal Revenue ServiceS The reason for this call is to inform you that IRS is filing lawsuit against you. To get more information
about this case file, please call immediately  on our department number 360-200-0899.  I repeat 360-200-0899. Thank you.
I received the first recording at 8:31 on my cell phone on 12/17/15.  I received the second recording on my home phone at 9:01
the same day.  Then at 3:54 again on my cell phone, then at 4:30 on my house phone. All in one day!!!!!

I received the same call twice today. I agree with you that it is not legitimate.