The NY Merchantile Exchange sued an alternate exchange on the grounds that its use of NYMEX settlement prices violated its copyright (background here).  The lovely and talented Copyfight pointed me to this law.com article on the  case.  If any of you out there are, represent, live with or just plain know arbitrageurs (traders who make trades based on the difference in price of the same goods in different markets), ask them how they will make a living if it turns out that the prices in one market can be copyrighted.