I heard there was a lot of unusual activity on United Airlines and Amrican Airline puts before the attack. They should be able to freeze anyones assets that they find traded unusual number of puts before the attack. www.creditsense.com
According to that article, every exchange is investigating his trading. The idea is to sieze his assets and dry up his money supply - there is some speculation that his personal fortune has been depledted, and he is getting his money from other sources, The stick market is one of them.