Ordinary citizens dislike being cheated or robbed. But something we tend to forget is that so do thieves: there is nothing like a dishonest fence to spoil their sleep. They cannot resort to the law, and, being criminals, they have an excellent reason not to trust one another. Thus, thieves need protection badly and, as a result, become particularly eager customers. Correspondingly, if protection is readily available, the temptation to embark on a criminal career increases, since it becomes easier to dispose of stolen goods or to avoid retaliation.

Diego Gambetta, The Sicilian Mafia The Busi…, loc. 84