On October 14, 1997, AU filed an amicus brief before the Ninth Circuit arguing against a district court’s ruling that the Free Exercise Clause gives landlords a right to discriminate against unmarried tenants on the basis of the landlords’ religious beliefs. The brief argued that activities that are of a secular character, and entered into for secular purposes, do not constitute the exercise of religion, and that, in any event, compliance with the state’s antidiscrimination law would not impose a substantial burden on the plaintiffs’ religious practice. A Ninth Circuit panel upheld the district court’s ruling. On August 4, 2000, the Ninth Circuit, acting en banc, vacated the panel decision, holding that the action, which had been brought by the landlords, was not ripe. On February 20, 2001, the U.S. Supreme Court denied the landlords’ petition for certiorari.