IRS Scam. DO NOT CALL THEM BACK. Federal agencies, nor any court or police department, will telephone you to demand payment. All such demands are done in writing. And, if the cops are going to arrest you, they don't give you a courtesy call: They show up with a warrant and handcuffs.

Robocall saying "The IRS is filing a lawsuit against you..."  SCAM

I've had two calls from 786-732-5443 this morning. They are leaving voicemails saying I need to call them back immediately.

I got 3 calls within 30 minutes! If you do dial it back it doesn't go thru, says international number.