Complaint Review: The Clearing House Mr. Adam Jaga

I received this letter stating:
Winning Notification
We are pleased to inform you that you are one of the declared winners of North American Lottery Inc held on April 10th, 2009 in the 2nd category. Ticket #50671 drew the lucky winning NO. 70770.
You are therefore entitled to the lum sum of $100,000. This is from total prize money of $500,000 US dollars that was shared and presented among the other 4 declared winners..... In accordance with our disbusement policy, your claim # has been assigned to our North American Claims Affiliate Mr. Adam Jaga. Your claim number must be kept private to avoid a double claim...

They sent along a check for $4800, wanting me to deposit it in my account and call them back for further directions on how to wire money to pay for the "government tax". When I called the number, I very straight forwardly asked if this was a scam, or a trick or something that was going to cost me money, and the "claim representative" said "No, this is for real. You really won $100,000." After talking to him I checked online and found more reports of this scam. Is it possible to stop these people from doing this? They are cheating people, as well as, lying in response to direct questions for there own personal gain at our expense.

Colorado
Colorado, Colorado
U.S.A.