There is no such thing as a technological solution to a political problem. Ultimately there is only one defense from this kind of grief i.e. make the price for it more than any of them are ever willing to pay.
They are more than willing to die for their cause.
What would that price be for a suicide bomber?
When it starts happening the media will blame it on Conservative rhetoric and the Jews. And that may just be the last of my buttons any of them will need or have a chance to press. In the meantime, carry whenever legal and possible and keep situationally aware in all public gatherings. Even or maybe especially in church. It’s surprising what caliber you can get to before it can be detected under a choir robe.
I don't think there is any way to stop the crazies unless it's to remove whatever motivation they might have. If they are fantisying about their families being able to get an official bombers trophy and $500 bucks, start sending death squads around to their friends, family and next of kin. With nobody to brag about them for blowing themselves up or nobody left to even remember their name, that might cut down on some of the bombings.
I'm sure there are better ideas, aren't there?
After all, it's an all-out war. Anything and everything goes to insure survival, especially if you are the peaceful one.
It's a simple question of kill or be killed. I say strike the vermin where they sleep and let the mosques sop up the blood.
LIVE FREE OR DIE!
If they are ready to die by suicide what would be a higher price?