In situations where accusations of widespread corruption, misconduct, unethical action, etc are made, a phrase that is often trotted out in defense of the accused is <i>"just a few bad apples"</i>. It's not WhereEver Police Department that has an issue with racial bias and violent escalation, <i>it's just a few bad apples</i>. Our school district does not have a bullying problem, <i>it's just a few bad apples</i>. Etc.<p>What is interesting about this cliched defense is that it is actually a malformed statement of the <i>original</i> cliche, "A few bad apples <i>spoil the barrel.</i>"<p>The original cliche refers to a phenomenon where overripe or rotten apples release ethylene gas, which is a ripening agent. This ethylene gas will accelerate the ripening/rot of nearby apples. If you are not <i>vigilant</i> in weeding out the bad apples, the rot will rapidly spread and soon there will be <i>no</i> good apples left to rescue.<p>Human "bad apples" don't release ethylene gas, but they corrupt their peers nevertheless. When a good cop backs the cover story of his corrupt cop partner, he becomes a bad cop as well. When prosecutors take up arms in defense of their corrupt prosecutor peers, they become no better than the initially targeted. If school administrators allow a bully to have his way for too long, then everybody else sees that they can get away with it too and before long you have daily fistfights behind the school at the end of the day.<p>Institutions that have had widespread unchallenged corruption for decades rarely need keyhole surgery, they need amputations.