In Bates v. State Bar of Arizona, 433 U.S. 350, 97 S.Ct. 2691, 53 L.Ed.2d 810 (1977), the Court held that disciplinary rules promulgated by a state supreme court pursuant to a constitutional grant of authority over the practice of law are directives of the sovereign which qualify for state action immunity. Id. at 359-63, 97 S.Ct. at 2696-99.