far been able to reach out and touch u.s. shores. they also, like isis, remained a top worry tonight, wolf. >> barbara starr, good reporting. thanks very much. a critical condition tonight. in light of our exclusive reporting, why hasn't the u.s. government issued a wider ban on laptops on board flights? let's go back to our justice correspondent, evan perez. are you getting any answers from the tsa? >> wolf, the explanation we got when the ban was first introduced a couple weeks ago is that u.s. and europeans layered security that greatly improved chances of detecting explosives beyond just screening equipment. now we reached out to the tsa to explain again why that is, knowing that these fbi tests showed security gaps. the homeland security department just commented to us saying in a statement that the u.s. government continually reassesses existing intelligence and collects new intelligence. this allows dhs and tsa to evaluate or processes and policies and make enhancement