WHEN Congress passed the Sarbanes-Oxley Act in 2002, after the Enron scandal, its target was big corporate fraud, not small fish. Yet in 2011 the law banning document-shredding sent John Yates, a fisherman, to jail. On November 5th the Supreme Court considered whether Mr Yates should have been charged under this law, which carries up to a 20-year prison term, for tossing undersized grouper into the sea.

The crime that spawned Yates v United States took place in 2007. A Florida official found that 72 red grouper on Mr Yates’s boat were an inch or two shy of the 20-inch minimum. Mr Yates received a citation and was ordered to bring the offending fish to shore the next day. Instead, the government claims, he asked a crew member to toss them overboard and replace them with bigger fish.

The government’s lawyer insisted that when the law condemns anyone who “knowingly...destroys...or makes a false entry in any record, document, or tangible object” to impede a federal investigation, tangible objects include fish. Mr Yates’s lawyer urged the justices to interpret the term in context.

Mr Yates’s supporters see the case as part of an epidemic of overcriminalisation in America. Justice Antonin Scalia seemed to agree. “What kind of a mad prosecutor would try to send this guy up for 20 years?” he asked. The government huffed that Mr Yates had concocted a “cover-up scheme” and had lied to law-enforcement officers. Chief Justice John Roberts was unconvinced: “You make him sound like a mob boss or something.” The justices will hook a decision by next June.