Federal authorities have arrested a man at the Orlando Intl. Airport who attempted to check a bag with materials that could have been used to construct an explosive device.
In 2005 there was an interesting article entitled Al-Qaeda's Inroads into the Caribbean In 2007 the TSA was alerted to be vigilant and to be alert to watch for Dry Runs, we know that Mohammed Atta, engaged in Dry Runs before 9/11
On Sunday, Terminal 2 at LAX was evacuated after a man reported writing in a restroom that indicated a bomb was in a Woman's restroom---within an hour Airport Police determined that there was no bomb and the terminal was reopened.