http://en.wikipedia.org/wiki/Confidence_trick
A confidence trick or confidence game (also known as a bunko, con, flim flam, gaffle, grift, hustle, scam, scheme, swindle or bamboozle) is an attempt to defraud a person or group by gaining their confidence.
The victim is known as the mark, the trickster is called a confidence man, con man, confidence trickster, or con artist, and any accomplices are known as shills. Confidence men or women exploit human characteristics such as greed and dishonesty, and have victimized individuals from all walks of life.