The lawsuit was brought against Apple by four iPhone users, who claimed that Apple was monopolizing the retail market for the sale of apps and using that monopoly to force higher-than-competitive charges for its apps.

The theory of the lawsuit is that Apple’s 30% commission charge to app developers is often passed on to consumers — creating a higher-than-competitive price — and that competitors are shut out because Apple prevents iPhone owners from buying apps anywhere other than its App Store.

Apple sought to block the lawsuit, asserting that it had not set the prices on the apps and thus the iPhone owners had no standing to sue.

But the 9th Circuit Court of Appeals ruled against Apple, and on Monday the Supreme Court agreed.