Another phone IRS scam...threatened us of imprisonment for tax fraud unless we pay 4500$ in 1 hour.

This is a Pakistan or India based IRS scam. Do not fall for it. The IRS does not initiate any legal action via phone.  
Read http://www.treasury.gov/tigta/press/press_tigta-2014-03.htm

As general background information, here are a few things you can do:
1) Report it to TIGTA under http://www.treasury.gov/tigta/contact_report_scam.shtml especially if you have become a victim (lost money, gave personal information etc.). You can also file a complaint with the Federal Trade Commission at ftc.gov/complaint (include “IRS Telephone Scam" in your complaint). This way you can also help the government establish specific fraud patterns.

2) Help kill their phone lines. The scammers use Voice over IP lines (e.g. magicJack (Ymax corporation)) to make it seem as if they are calling from the US. This is always against these companys' terms of service and can lead to immediate termination of their contract and blocking of their IP addresses for future attempts to register. Do a reverse look up of their telephone number (e.g. www.whitepages.com) to identify the Voice over IP provider and report it to the company and/or law enforcement (local police and/or state attorney general)

3) 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 provide US law enforcement agencies with the political backing and the resources they need to work in India and Pakistan together with local authorities (it can happen, read: http://www.ndtv.com/article/india/ex-call-cen ... mmission-320427). A US task force has already been set up in Jamaica to nab scammers there (see http://www.ice.gov/doclib/news/library/reports/cornerstone/cornerstone7-1.pdf). You can use the following template for your letter (more powerful!) or email:

http://800notes.com/forum/ta-a9526ebadc65cf9/ ... 558497927242748

Just called me and said I owe IRS. When I aksed how come IRS did not send me notice already, he said we did 2 times. I said to what address...he gave me my 7 years ago address!!! I said ok how come you do not have my current address...he just hang up ;)

I got the same call yesterday. The guy identified himself as DETECTIVE STEVE PETERSON from IRS. He said I had three hours to come up with $5000 or  he would send local enforcement to pick me up and throw me in jail. I told him to get lost and
hung up. I will definitely file a complaint.

I got a call from department of grants in Washington dc the foreign man told me because I had no criminal background and pay my taxes on time I was eligible for a grant of 9000 dollars when I refused to give him my checking info he said he could send it western union and transferred my call to someone else. The person that I then spoke to told me I had to buy a money pack green dot and load 250 dollars on it to get the grant I just hung up.