Family members of victims of the 1999 North Valley Jewish Community Center shooting, in Granada Hills, California, filed suit against the firearms manufacturers, dealers, and distributors of the firearms used in the shootings, claiming negligence and creation of a public nuisance by the gun industry. The defendants successfully moved to dismiss the action in the District Court on the basis of the 2005 federal immunity law. Plaintiffs have appealed that ruling. This amicus brief was filed in support of the plaintiffs' appeal, arguing that the case falls within the immunity law's exception for actions alleging knowing violations of a statute "applicable to the sale or marketing" of firearms, and that the law is unconstitutional because it violates the separation of powers doctrine and constitutes a "taking" of a protected property interest in violation of the Fifth Amendment.