The 1977 movie right? That's why I felt okay to post it. It's not like it's giving them an idea that is obvious to anyone. Even the teenager who flew his plane into the Tampa office building left in his suicide note that Bin Laden planned to attack the Superbowl. So if he hadn't already thought of it, well, then he did after that.
Hey, there was a Tom Clancy novel in which a 747 flew into the Capitol building during the State of the Union address. The difficulty is not in planning these spectacular attacks, but in executing them.