The weapon that I carry with me on every flight - is my trusty laptop.
As it happens, I have a lighter one at 1.2Kg but the big ones weigh in at 2 or 2.5Kg. If you were to swing one of those at another human's face, or the back of their head, it would cause severe damage.
Curiously, I have never had my laptop confiscated, Actually, they encourage us to bring them on board as they provide power hook ups and now want to makes lots of money from on-line access.
Of course, I am tongue in cheek about this and they have to find a balance between what they can remove and what they cannot but if they have it wrong on the detail, then I reckon they have it wrong at the high level too.