The Supreme Court ruled Monday that a 66-year-old program that lets the government take raisins away from farmers to help reduce supply and boost market prices is unconstitutional.

In an 8-1 ruling, the justices said forcing raisin growers to give up part of their annual crop without full payment is an illegal confiscation of private property.

The ruling is a victory for California farmers Marvin and Laura Horne, who claimed they were losing money under a 1940s-era program they call outdated and ineffective. They were fined $695,000 for trying to get around the program.

A federal appeals court said the program was acceptable because the farmers benefited from higher market prices and didn't lose the entire value of their crop.

The government argued that the Hornes benefited from increased raisin prices, but their cause had won wide support from conservative groups opposed to government action that infringes on private property rights.

Writing for the court, Chief Justice John Roberts said the government must pay "just compensation" when it takes personal goods just as when it takes land away. He rejected the government's argument that the Hornes voluntarily chose to participate in the raisin market and have the option of selling different crops if they don't like it.