These days, calls for criminal justice reform are loudest on the political right. Corrections reform has advanced rapidly in conservative states likeTexas and Georgia; Republicans like Mike Lee and Rand Paul are vocal advocates for reforming mandatory minimum sentencing; and Koch Industries is involved in a major project to improve indigent defense.

There are many reasons conservatives are engaging so deeply with criminal justice. One notable reason is that they tend to notice creeping “overcriminalization,” causing them to reflect more broadly upon the entire justice system.

Overcriminalization refers to the increasing use of criminal law to punish thousands of ordinary activities that traditionally have not been considered crimes. It is indicative of dysfunction in the way we use criminal law, and it is particularly harmful for individuals and small businesses that often cannot afford elite lawyers to help them navigate onerous legal proceedings.

The Case of the ‘Missing’ Three Fish

Consider the case of John Yates of Holmes Beach, Florida. In 2007, a state law enforcement officer boarded Yates’s ship in the Gulf of Mexico to inspect his catch of more than 3,000 fish. The officer accused Yates of catching 72 undersized red groupers and ordered him to bring the ship ashore, where he—along with several federal agents carrying weapons—counted only 69 groupers. Yates was accused of disposing of evidence by throwing fish overboard. Yates believes the fish were incorrectly counted, but even if the officer was correct, what happened next was bizarre.

An appeals court upheld Yates’s conviction, but on Wednesday, the Supreme Court reviewed the case. Yates argued that the prosecutor is presenting a fanciful reading of Sarbanes-Oxley, one that a reasonable person could not anticipate.A federal prosecutor charged Yates with violating the “anti-document-shredding” provision of the Sarbanes-Oxley Act passed in the wake of the Enron accounting scandal. The prosecutor argued that the statute prohibits the destruction of tangible evidence, and because 69 rather 72 groupers were counted upon re-inspection, Yates had likely run afoul of the law. The anti-shredding violation is punishable by up to 20 years in prison.

A Surprise, But Welcome, Supreme Court Pick

Court-watchers were surprised that the justices accepted the case out of approximately 10,000 petitions for certiorari. The court, however, seems increasingly concerned about prosecutorial excesses. Last year, it unanimously decided against the government in United States v. Bond, a case in which a jealous wife tried to give her husband’s lover a skin rash using household chemicals she had purchased on Remarkably, a federal prosecutor charged the wife with violating an international chemical weapons agreement.

Yates’s case should be an obvious one for the application of lenity. The lower court could have used the rule to determine whether groupers constituted “tangible things” in the sense implied by Sarbanes-Oxley’s anti-document shredding provision. It did not. For those who follow trends in criminal law, this disregard is unsurprising. Justice Antonin Scalia, a staunch defender of the rule, has fumed that “[i]f lenity has no role to play in clear case[s]…we ought to stop pretending it is a genuine part of our jurisprudence.”One interesting issue the court may consider in U.S. v. Yates is the Rule of Lenity. This canon of statutory construction advises that when there are two reasonable readings of a criminal statute, the statute should be interpreted in the manner most lenient to the defendant. The rule forces the burden of precise drafting on legislators, and it discourages convictions unless individuals have fair notice of the law. In an 1820 opinion, John Marshall described it as an “ancient maxim.”

The events in Yates’s case add up to a consummate story of overcriminalization—but it is not the only story. There are now so many federal criminal statutes (almost 5,000), and prosecutors can so broadly interpret them, that anybody can be accused of anything at any time. Americans have been threatened with prosecution—and in some cases served prison time—for importing lobsters in the wrong container, mislabeling paperwork on orchids, and helping injured animals.

Dysfunctions like this in American criminal justice cost taxpayers an extraordinary amount of money, expand the size and power of government, often ignore the needs of real crime victims, and fail to prioritize actual public safety needs. Prosecutors undoubtedly perform a valuable service for Americans, but they can become overzealous—and thus counterproductive—like anybody else. Yates’s case is emblematic of a profession that is going a bit overboard. With any luck, the Supreme Court will reel them back in.

Vikrant P. Reddy is a senior policy analyst for Right On Crime, a project of the Texas Public Policy Foundation, a non-profit, free-market research institute based in Austin, Texas.