“I want to ask a question. What is a loophole? If the law does not punish a definite action or does not tax a definite thing, this is not a loophole. It is simply the law. Great Britain does not punish gambling. This is not a loophole; it is a British law. The income-tax exemptions in our income tax are not loopholes. The gentleman who complained about loopholes in our income tax – he did not refer to the exemptions – implicitly starts from the assumption that all income over fifteen or twenty thousand dollars ought to be confiscated and calls therefore a loophole the fact that his ideal is not yet attained. Let us be grateful for the fact that there are still such things as those the honorable gentleman calls loopholes. Thanks to these loopholes this country is still a free country and its workers are not yet reduced to the status and the distress of their Russian colleagues.”

–Ludwig von Mises, Defense, Controls, and Inflation

The “loophole” in question, of course, is that prosecutors have essentially absolute discretion to not enforce the law.