Under the doctrine, which the Supreme Court has recognized since 1908, you can resell your stuff without worry because the copyright holder only had control over the first sale.

Put simply, though Apple Inc. AAPL -2.13% has the copyright on the iPhone and Mark Owen has it on the book “No Easy Day,” you can still sell your copies to whomever you please whenever you want without retribution.

That’s being challenged now for products that are made abroad, and if the Supreme Court upholds an appellate court ruling, it would mean that the copyright holders of anything you own that has been made in China, Japan or Europe, for example, would have to give you permission to sell it.

“It means that it’s harder for consumers to buy used products and harder for them to sell them,” said Jonathan Band, an adjunct professor at Georgetown University Law Center, who filed a friend-of-the-court brief on behalf of the American Library Association, the Association of College and Research Libraries and the Association for Research Libraries. “This has huge consumer impact on all consumer groups.”