Fraud was a crime in which a person misrepresented themselves for personal gain. A confidence game was a form of fraud.
In 2268, Harry Mudd faced the death penalty on Deneb V for fraud for selling patents that he didn't have the right to sell. (TOS: "I, Mudd")
In 2269, Mudd was wanted for fraud again following his sale of love potion crystals to the inhabitants of Motherlode, as well as having sold the Starfleet Space Academy to the inhabitants of Ilyra VI (TAS: "Mudd's Passion")
In 2370, twelve outstanding arrest warrants for fraud and petty theft existed against Yranac in the Klingon Empire. (TNG: "Gambit, Part I")