Wednesday, the Supreme Court heard arguments in a case that will determine whether a Florida fisherman, alleged to have thrown undersized fish overboard, was properly convicted under a law passed to stop the crimes committed by the corrupt executives who brought down Enron.

In 2007, Captain John Yates was fishing off the coast of Florida when the National Marine Fisheries Service (NMFS), whose officers were deputized as federal agents by the National Oceanographic and Atmospheric Administration (NOAA), inspected his boat. These agents claimed that Yates had caught undersized fish and instructed him to return to shore for inspection. Before the boat reached shore, Yates allegedly told his crew to throw some of the fish overboard, an act that typically results in a $500 fine or temporary license suspension.

Nearly three years after the fact, federal prosecutors charged Yates under the Sarbanes-Oxley Act (SOX)—the sweeping legislation passed after Enron’s collapse to crack down on securities and accounting fraud. The federal government argued that throwing fish overboard was “shredding” of “tangible evidence.” “Shredding” is a severe crime under SOX, carrying a maximum 20-year prison sentence.

SOX’s anti-shredding provision was meant to stop executives from destroying files, not imprison fisherman for throwing fish back into the sea.

Captain Yates was convicted. He appealed and the Supreme Court took his case.

Congress intended SOX to “protect investors by improving the accuracy and reliability of corporate disclosures made pursuant to the securities laws,” and to “safeguard investors in public companies and restore trust in the financial markets following the collapse of Enron Corporation.” Put simply, SOX’s anti-shredding provision was meant to stop executives from destroying files, not imprison fisherman for throwing fish back into the sea. That’s why one of the bill’s authors, former Representative Michael G. Oxley, filed a brief supporting Yates.

Yates could never have known or imagined that SOX criminalized throwing undersized fish overboard. And questions from the Justices to the government reflected their skepticism at the government’s claim that it did.

Justice Stephen G. Breyer said the law, which is “far broader than any witness-tampering law, any obstruction statute, any lying to a federal agent law…” could mean a person who throws away a government form delivered by a mail-carrier was a felon. He asked for a limiting principle on government power.

Justice Samuel Alito, citing the possibility that a person who threw back a single trout caught on federal land could be at risk of prosecution for “shredding.” He also asked for a limiting principle. The government, however, recognized none.

As is almost always the case in regulatory overcriminalization cases, Captain Yates’s punishment far outweighed the “crime.”

As Chief Justice John Roberts said as the government’s attorney was describing Yates’ behavior, “You make him sound like a mob boss or something.”

Captain Yates spent 30 days in prison with three years of supervised release. He suffered DNA collection and travel and financial restrictions, and has all but become a pariah in the fishing industry, effectively losing his ability to earn his living by doing what he loves.

Cause of Action saw overcriminalization at work when we defended California marine biologist Nancy Black against NOAA’s effort to imprison her for up to 27 years for misdemeanor whale feeding. Although Cause of Action and the rest of Ms. Black’s legal team were able to spare her from jail time, her loss of grant funding, years of fighting the government, and reputational damage to her business took a heavy toll.

Unfortunately, the effects of overcriminalization are not limited to just one marine biologist in California or one fisherman in Florida. If the Court allows Captain Yates’s conviction to stand, it could open the floodgates to even more abuse by federal agencies that selectively enforce regulations through the criminal law and send the message that the government is above the law.

During the years that Captain Yates was stuck in the legal system there were multiple cases of document destruction by federal officials but no SOX prosecutions.

In 2011, during the course of an Inspector General investigation into NOAA’s Office of Enforcement (the agency that investigated Yates), then director Dale J. Jones, Jr. actually did shred documents to conceal evidence, conduct clearly prohibited by SOX. Jones was not prosecuted—instead, he was given a different job.

Similarly, Charles Edwards, former Department of Homeland Security Inspector General, allegedly destroyed documents to impede a federal investigation into his office. Edwards, too, was reassigned to another federal job.

This is an obvious double standard: a federal employee who destroys documents to obstruct an investigation, conduct clearly covered by SOX, is reassigned, while a taxpayer who orders fish thrown overboard is imprisoned.

No system that treats government employees differently than average citizens engenders respect for the law. Moreover, the differential treatment of taxpayers and government officials suggests that SOX is so vague that prosecutors cannot apply it consistently.

None of this is to say that criminal activity should go unpunished, or that laws shouldn’t be applied as written and intended—they unquestionably should. But overzealous federal agencies should not have free reign to reach into federal criminal law to create ways for unsuspecting citizens to be prosecuted. That cannot be justice. Therefore, the Court should reverse Captain Yates’s conviction to halt agency abuse.

Dan Epstein, is executive director of Cause of Action, a non-profit government oversight organization which filed an amicus brief in Yates v. United States.