Yesterday I received two calls from this number and left one message. He claimed to be IRS officer David Jackson and wanted me to call them immediately as it was an "extremely time sensitive matter". He warned not to disregard the message as there is tax deficiency.

I got a call from (414)690-1141 called ID said VOIP CALLER. I made the mistake of answering the phone. A guy with an Indian accent claiming to be with an investigations unit of the IRS claiming I owed money for 2012. I questioned the caller ID as well as his lack of professionalism. I asked for his name or ID# and he refused to give either to me. I stated that I thought he was a scammer and that's when the colorful language started. I told him I was going to call the IRS directly and I hung up. While I was on the phone in queue with the IRS, he called back 6 times. I've blocked the number and will be reporting it to the IRS and the FCC.

I made a typo in my original post. The number is 415 690-1141 (not 414 690-1141)

These calls originate in India.  They spoof US  202 area code because it is Washington DC.  Just ignore 'em.  Complain to police.  Or local Attorney General.  They've called me.   You can always hear Hindi voices in background.  Total scam!

I called the number they gave.  Told them that the US Navy had launched a Hellfire missile against his building because all Indian scammers are now considered terrorists and that the US NSA is monitoring all calls coming in to US.  He hung up pretty fast, but I think I got most of the information to him.   Maybe they'll think twice about scamming Americans.

I think the US NSA does monitor all calls coming in to US.