George Leef’s latest Forbes column explores a courtroom battle pitting the federal government against FedEx.

One such case recently crashed after almost two years of legal skirmishing in federal district court. The crime the feds were going after was an imaginary conspiracy between FedEx officials and online pharmacies to ship sleep aids, sedatives, painkillers and other medications to customers who didn’t have valid prescriptions. Somehow, FedEx was supposed to know which packages were illegal.

Of all the lunacy brought about by the war on drugs, it’s hard to top that.

For one thing, the company had repeatedly told federal officials that they would stop dealing with any shippers known to be sending illegal drugs. All they needed was a list of such shippers, but the government refused that offer of cooperation. One might therefore conclude that going after a high-profile corporate defendant for a gigantic fine ($1.6 billion) was of more interest to the prosecutors than stopping some illicit shipments.

Another glaring problem with the prosecution’s case was that it is clearly barred by federal statute. Congress, apparently suspecting that overly ambitious prosecutors would aim for scalps by going after big national carriers, wrote an exemption for common carriers into the Controlled Substance Act. Carriers like FedEx are allowed to transport the substances covered by the CSA as long as they do so “in the usual course of business.”

Nothing suggested that FedEx had somehow deviated from its usual business in taking and delivering packages that happened to contain illegal medications, but the prosecutors devised a new interpretation of the law under which the exemption only applies to shipments of medications that were dispensed “within lawful channels.” Nice try, but Congress did not write that into the law and prosecutors don’t have the authority to amend statutes to suit their convenience.