"...inform you that IRS is filing a lawsuit against you.  To get more information try to reach on our immediate department number which is (320) 207-9237.  I repeat (320) 207-9237.  Thank you.

It's a scam and should not be responded to.  I received the same call 10 minutes ago.  They're apparently pretty busy today.  http://philadelphia.cbslocal.com/2014/11/06/i ... ending-lawsuit/

Same message at about the same time

Same message from them earlier today

Left voicemail saying a lawsuit is being filed against me and to call 320-207-9237 to get more information.  Other posts on this number say it is IRS.  Probably 100% scam to get information about you.