Never, this is all these people know. They are truely ignorant which makes the 87% figure very believable. The amazing thing to me is that 13% are against violence or at least are not sure.
Ignorance doen't give them a pass however. They are dangerous even though ignorant. Being ignorant, however, can can kill you in this world. When ignorance picks a fight with smart, smart wins every time. The laws of "Natural Selection" are going to be very hard on the Palistinians I am afraid.