In every single terrorist attack, whether successful or not, the perpetrator has had one common defining factor.
This factor is so definitive, so unavoidable and so unequivocal that you could actually profile for this with 100% success.
Yes.
The answer is clearly to prevent human beings from boarding aircraft.
This will achieve the oft-sought goal of reducing our risk of being blown out of the sky to zero.
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So you make people carry their liquids on board in a transparent bag, or prevent them from carrying them on at all.
They'll just shove them up their arse on a bit of string.
Remember, these people are prepared to die for their cause. A little rectal discomfort isn't going to put them off.
So. What do you do about that? Anal probes for all?