The federal Hobbs Act makes it a federal crime for any government official, including police officers, to extort money from citizens "under color of official right." "Under color of official right" simply means that the police officer, (or other government official), has used his or her badge, or official position, as a means to improperly shake you down and take your money.
As a former federal prosecutor, I prosecuted a wide variety of state and local government officials who improperly used their public offices for private gain. For instance, I once prosecuted a social agency case worker who extorted kickback payments from a foster parent in exchange for getting the foster parent a higher per diem payment for taking care of a special needs foster child. Extortion also occurs when a city licensing inspector demands money from a business owner in exchange for "looking the other way" as to city code violations. The examples are endless. But perhaps the worst kind of extortion cases involve crooked police officers who demand money, sometimes alongside the highway, in order to make traffic tickets disappear.
Have you ever heard of similar examples of extortion committed by public officials? Do you believe such extortion is rare?