Subject states he is an agent w/ the federal govt. Threatened to "take me down" if I did not wire $$ to him to settle a debt that I supposedly owe. When I started questioning him he began backtrackimg and at one point became unprofessional telling me I'm "trying his patience".

I got the same phone call at work today, and I went to the police department and they called them.The so called FBI agent hung up on the officer. Was his name "Harvey"

THIS IS AN EXTORTION SCAM. Scammers pretend to be law enforcement (police, sheriff, Feds, AG's Office, fake cop agencies with made-up names) and may be using bought/hacked/phished loan application data to extort money or personal info for fictitious crimes.
The real DEA warns about fake-DEA extortion scams here http://www.justice.gov/dea/pubs/states/newsrel/2010/denver111010.html 
The real FBI warns about payday loan extortion scams here http://www.fbi.gov/news/pressrel/press-releases/paydayloanscam_120710 
The real FBI warns again http://www.fbi.gov/news/pressrel/press-releas ... nt-payday-loans 
The real FDA warns about fake-FDA extortion scams here http://www.fda.gov/NewsEvents/Newsroom/PressAnnouncements/2009/ucm195814.htm 
The real FDIC warns about fake-FDIC extortion scams here http://www.fdic.gov/news/news/specialalert/2010/sa10131.html 
Report to the Internet Crime Complaint Center http://www.ic3.gov/complaint/default.aspx , the Federal Communications Commission http://esupport.fcc.gov/complaints.htm , the Federal Trade Commission https://www.ftccomplaintassistant.gov/ and your state AG http://www.naag.org/current-attorneys-general.php as appropriate.

I got the same thing from A "Agent Harvey" he also said I owed a debt and was facing 5 years in prison and a fine of up to 10.000 to 15.000 dollars. He was very rude and a jerk. He threatened me and my family. He keeps calling me and making me very upset. He is very persistent please be aware of this number and man.

Yes..I have just received a call from "Harvey" on my cell phone, as well as my work... (it was Officer Smith that called my work)..... I am frigging fed up with this crap.