That is the number of times suspected terrorists, those on actual watch lists, successfully bought guns or explosives in the good ole US of A over the past five years. Why? Because of the Terror Gap. That is the space in our law created by right wingers with celery-stalks-for-brain-stems, bed-wetting Blue Dogs, and neglectful progressives that allows those on watch lists to pass background checks when purchasing weaponry that kills. You can't get on a plane--but you can buy a freakin' explosive.
Even Rahm agrees! (or at least he did):
Remember, conservatives are in a corner shivering over the prospect of KSM being tried in New York, but if a member of Al Qaeda buys a cache of guns the FBI won't know about it and the any background information given when purchasing said weapons is destroyed faster than you can say Nidal Malik Hasan or Eric Rudolph. Now that seems just downright crafty!
Learn more about how you can close the Terror Gap, so that our laws to protect the homeland make just a modicum of sense.
Full Disclosure: I happily advise Mayors Against Illegal Guns