RACKET

(CRIME) [noun] [C] [informal] - a dishonest or illegal activity that makes moneyThey're involved in a drug-smuggling racket.He was caught running a prostitution racket in London.They claimed that the business was the victim of a protection racket (= was being forced to pay money to a criminal in order to prevent them being damaged by that criminal).Telephone chat lines are a bit of a racket/a real racket (= are considered dishonest although they are not illegal).