Title VII of the Civil Rights Act of 1964 prohibits, among other things, employment discrimination based on religion. That's great, but what about volunteers? Sister Michael Marie and Sister Mary Cabrini, two Catholic nuns, were Red Cross volunteers in Chillicothe, Ohio.
They were never employees, but they believe the positive reviews they received over the years should have entitled them to "promotions" that would have altered their roles and responsibilities. They never received those promotions -- because, they alleged, the Executive Director of the local chapter of the Red Cross was biased against them because they were "traditional" Catholics.