Says I owe Irs $4000+ in Taxes and there is a warrant out for my arrest

There is a widespread IRS (or CRA) or "tax scam" being  practiced by scammers on both USA and Canadian residents.

USA tax payers should read this:
http://www.irs.gov/uac/Newsroom/Phone-Scams-C ... 5-Filing-Season

Canadian tax payers should read this:
http://www.cra-arc.gc.ca/nwsrm/lrts/2013/l131210-eng.html

Short answer:
The IRS never initiates a contact via phone.
They always send a snailmail first.

Educational post:
This scam is also described as scam #11, here:
http://phonehelp.2truth.com/facts.html

If you were contacted by an IRS impostor, you may file a report, after clicking on this link:
http://www.treasury.gov/tigta/contact_report_scam.shtml

UPDATES:
Recent news story:
http://www.wltx.com/story/money/2015/03/12/fa ... -scam/70202814/

Congressional hearing:
http://www.nbcnews.com/business/taxes/tax-imp ... hearing-n341906

i called him back and ask if i could meet him somewhere to give him the cash in person......he hung up!

Scam artist keeps calling me.

David Gray said there is an enforcement action against me and to call to avoid a federal indictment?