Its the IRS scam, and its all over this board. It has even made the national news. The scammer demands immediate payment of over due taxes. They must be payed by wiring the money or by giving the scammer your credit card or bank account number. The scammer threatens you with arrest.
The IRS never makes initial contact by phone. They never demand immediate payment. The caller is a scammer. Do not send him any money. Report him to the real IRS.
A recorded message from 240-204-9424 basically stating the same except the message didn't start out identifying himself with the IRS., He didn't have broken english, was well spoken and the message said he was calling before I needed to appear before a grand jury for committing a Federal Criminal Offense. Then went on to say, "To speak with a Federal Agent call 240-204-9924', then repeated the number. Perhaps they hired a professional announcer to record this canned message after complaints of broken english :P- Anyway, I came here to find similar scam reports.