SCAM  Auto dialer with computer voice claiming to be the IRS.  Left message that heavy fines could be avoided if I returned the call.

Got the same message today.

I just received the same phone message indicating a sherrif waas coming to arrest me for tax fraud.
When asked for a reference number to my "case" they hung up. It is very unsettling.
Perhaps the IRS should be made aware of this

The IRS is very aware of this situation.  There is information on the official IRS website.  These scammers are probably on India!

This a Pakistan based IRS scam (there are also Indian based ones). Do not fall for this. Read http://www.treasury.gov/tigta/press/press_tigta-2014-03.htm
The IRS does not initiate any legal action over the phone. The scammers use voice over IP lines (in this case magicjack (Ymax corporatiion). This is against the company's terms of use and can lead to termination of their contract. However only law enforcement can initiate the contact if you yourself are not a customer. So report it also to your local law enforcement agency. Ultimately this is a case for the FBI legal attache in Islamabad. If you are really annoyed: call or write to your representative in Congress. As these scams happen all over the country maybe this will trigger a reaction (and the NSA can finally be a force for good).