There is a fairly common IRS or "tax scam" being practiced by scammers in both Canada and the USA.
USA tax payers should read this:
http://www.irs.gov/uac/Newsroom/IRS-Reiterate ... -Telephone-Scam
Short answer:
The IRS never initiates a contact via phone.
They always send a snailmail first.
I got a call from this number 202 803 5028. And they told me that I have not paid taxes worth $1900. They also told me that my name is under a criminal investigation. I am a student. I'm a person who respects the law. So, they told me if I am not going to pay, the whole amount then they will arrest me and my daughter, she is 10. She heard this conversation and she was crying. She says "dad please pay the whole amount because I don't want to lose you". I said ok I will pay. The guy with Indian accent said "ok, don't turn off your cellphone and I will give you guidance on how to pay the amount of money". He said I should I go to CVS or 7/11. I went there and the whole time he was on the phone and was guiding me. When I entered 7/11, he said I should take a card called "green dot money pack". I did. And he told me to pay via this card. Afterwards, I understood that something's fishy. I told him I can't pay via this card because it doesn't quite make sense. I said give me your bank account number to pay by credit and he said "no you will have to pay by an hour or you will be arrested". I finally told him that I'm not going to pay through this card and he suddenly hung up. I lost my time and felt frustrated.