The best way to defend against them is to have as many of the citizenry armed as possible so as to interdict them immediately as they happen.
FRegards.
It makes sense...shoot up an American branch of El Al, the Israeli airline. Two birds, one stone, and boom, two dead yummy birds!
I hope I'm packing and able to shoot when Manuel hits the Foothills Mall. Boom! Dead, yummy terrorists!
Apologies to Joss Whedon and actress Clare Kramer (Buffy the Vampire Slayer).