Antitrust policy was also directed against anticompetitive industry conduct. The Supreme Court ruled against price collusion outright and ruled against price discrimination if it substantially lessened competitive or tended to create a monopoly. Specifically, the Court ruled illegal not only cartels but also any informal understanding or collusion to share the market, fix prices, or establish price leadership schemes. Conscious parallelism (i.e., the adoption of similar policies by oligopolists in view of their recognized interdependence) was ruled to be illegal when reflecting collusion. Thus, the Supreme Court ruled against the there large tobacco companies in the 1946 Tobacco case (conscious parallelism was believed to have been the result of collusion in the from of price leadership), but ruled to drop the suit in the 1954 Theater Enterprises case (collusion could not be inferred from conscious parallelism).