The Supreme Court ruled Tuesday that textbooks and other goods made and sold abroad can be re-sold online and in discount stores without violating U.S. copyright law. The outcome was a huge relief to eBay, Costco and other businesses that trade in products made outside the U.S.

In a 6-3 opinion, the court threw out a copyright infringement award to publisher John Wiley & Sons against Thai graduate student Supap Kirtsaeng, who used eBay to resell copies of the publisher's copyrighted books that his relatives first bought abroad at cut-rate prices.

Justice Stephen Breyer said in his opinion for the court that once goods are sold lawfully, whether in the U.S. or elsewhere, publishers and manufacturers lose the protection of U.S. copyright law.