On Tuesday, the Supreme Court [made] a forceful declaration of the limits of copyright law. The justices ruled, 6 to 3, that the first-sale doctrine applies no matter where a copy is made, as long as it's done in accordance with U.S. law. The decision in  provides clarification that Americans are free to redistribute the copies they own that were legally made and sold overseas, just as they are with the copies they buy in the United States.

That's a key point. Courts shouldn't assume that copyright law was designed to protect copyright holders' slowly evolving business models. If Congress wants to outlaw the kind of "gray market" importing that Kirtsaeng practiced, it can do so explicitly. But there are many other industries that have found ways to deter those practices without the aid of copyright law - for example, by using contracts to keep tight control over foreign retailers. Courts have to balance copyright holders' interests against the public's ability to access those works and exercise the rights of ownership.