Whenever there is a particularly heinous crime people call for the death of the perpetrator. It is the case that in some cases, that person does that act because they believe they will be rewarded in heaven. I don't want to associate this post with any particular religion(s) by the way, though I think that may be inevitable.
Now look, in Jannah you get whatever you want, including a Haram things. And yet, simply being gullible enough to believe isn't enough apparently and you get these people who say you conduct certain actions to increase your reward in paradise. Contradiction - much?
I was just watching a documentary about the destruction of historic sites in Iraq and Syria. I was on the verge of tears. And it's clear these people want to die. So I thought, if the suicide vest of a combatant fails and they get captured, what do we do to them? They don't deserve to live but equally they don't deserve to die - because that's what they want, and we don't want to give them what they want. Keeping them alive in a prison is obviously expensive, and they're bound to die eventually.
Clearly my post will be clouded by strong emotions given what I have just seen. I can think of many ways these people could be punished, though I'm not sure I want to sink to their level. I was thinking a good punishment would be to chain them up and force them to listen whilst someone reads out all the scientific errors in their religious text(s) and points out anything else wrong too. And you keep doing this until they get the message. That way, they might start to feel bad.
When I save Daesh parading people in cages it reminded me of
the story of the ninth Guru of the Sikh religion, Guru Tegh Bahadur, who was also paraded whilst in a cage, during Mugal times in India. Interesting side note: To me, a
Dastaar has the complete opposite effect of a balaclava or a
Niqāb, because Sikhs have always been on the side of the oppressed and have never been the oppressors...