is there anything you could share with us, i don't want you to divulge secrets of course, that would prompt you -- this heightened watch? i know they are not calling it alert, but watch. what was behind it? >> first, it is consistent with the waiter risks operate. to try -- with the way terrorists operate. to have targets and timing which would add to any disruption they could cause in our culture. i think we would want to be on a -- to keep our antenna up. i'm not privy to the kind of intelligence that provided the basis for this. having been in the chair when you had to make a decision about whether to share such things with the american people, i think you err the side of caution. particularly when you understand the audience, people know not to suspend their activity they know it is