Don't call them. If you call they'll know you listened and that makes you a target for more scams, more calls.
They are probably using a spoofed number or a VOIP number. The call is really coming from outside the US.
Telephone scamming is not high priority with law enforcement. The few scammers in the US know that. They move often and law enforcement doesn't have time to track them down.
Call at 8:54 am on 03/18/2015 from Bill Connors of the IRS tax fraud dept. saying they had enough to issue a warrant for my arrest and I should call back urgently.
Report the Calls to the real IRS here:
•report the incident to the Treasury Inspector General for Tax Administration at 800-366-4484.
•You can also file a complaint with the Federal Trade Commission at FTC.gov. Add "IRS Telephone Scam" to the comments in your complaint.
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Do consider getting a call blocking device or phone.. You can google them and many are around $50.00 or so.If its a cell phone, some already have call blocking, if not, there are free apps on the web that will work for some. You can google this. If you have a smart phone, there is a free app called call control. Iphones appear to have apps also. Another one is called Mr. Number.
Received call at 9:40am, Friday, March 20, 2015. Male with accented voice saying that this was the IRS! I told him: Bulls**t, the IRS doesn't call. Hung up. Let's see if I get more calls.