People that were shocked at the idea of a futures market in terrorism and other global events had probably never understood the term "futures market" to begin with. It was a great idea. Though it had questionable utility given the nature of deliberately hidden information before terror attacks, it would have been more useful in guessing things like revolutions.
An interesting and related situation is when large blockholders in corporations simultaneously hold significant short interests in derivatives of their company shares. This is espescially useful when a value destroying acquisition is on the table. If the blockholder also owns a significant portion of the target, they can use their block to force the acquistion, profiting from the gain in the target and the loss for the acquirer.
