Viewer discretion is advised: Graphic Video.

 www.liveleak.com/view

I've seen worst, a man being cut into pieces by cartels.
I can't paste it here, that site liveleak.com has..
a human decapitation
throat slit..
penis amputation ..
beheading
it's right on that site..

I don't understand why they do it(this video you posted), for their belief?? 

there is another japanese version, this guy kills himself but stabbing knife right into his abdominal, forcing it in to his heart, screwing it while can and dying painfully..
Later I learned it's some traditional samurai thing, dying with dignity or something like that..

I would never understand these things..

Pagal musalte haru. Sab kaa sab terrorist haru.

This shows they've disregard for their own life and others, isn't it?

' Mind Out Of Order '
They are brainwashed by their culture and religion in a negative way. Wrong software is loaded inside their brain from their birth, now they are functioning according to the software. They won't change and they can't see what is wrong they are doing. They need to filter their beliefs which they won't do. They need to take it (religion) easy.