Under a little-known state law, Wisconsin residents can be prosecuted if they enter a marriage outside the state that would be illegal in Wisconsin, with penalties that include a $1,000 fine and up to nine months in prison. In 2006, voters approved a constitutional amendment that defines marriage as being between a man and a woman.

After the California Supreme Court ruled a state ban on gay marriage unconstitutional, Fair Wisconsin, a gay rights group, e-mailed 10,000 of its supporters, the Milwaukee Journal reported. The group warned two couples who said they were considering California weddings of the potential consequences.

"I'd rather be prosecuted than persecuted," one person responded.

Julaine Appling, executive director of the Wisconsin Family Council, said the state should enforce the law.