Talk about meta-data....
“....We picked up some DNA from that explosion last weekend, and it seems there’s a 95% chance that person was your first-cousin, or closer. Anything you want to tell us, Achmed?”
As a means of control, it sounds workable. Being able to identify somebody suspected of “crimes against the State” AND know who all his close relatives are as potential targets for reprisals, would do a lot.
I personally think the suicide bombers are depressed, and dying in jihad is the only acceptable way of suicide. If jihad activities mean that every male in your clan is killed, and all the females shipped off to brothels, families might be less enthused about potential jihadis among them.