A lot of the Christian saints are martyrs as well. I'm sure that other religions/groups have their martyrs too.

I wouldn't consider these hijackers martyrs though. Merriam-Websters Collegiate Dictionary (see www.yourdictionary.com) has a definition:
martyr
2 : a person who sacrifices something of great value and especially life itself for the sake of principle
but I don't think these people valued their lives, and what was the principle?? Hatered or the wish to inflict harm on others is no principle. No, these people aren't martyrs!

(list 6284, Mk1 S/N 00299 4GB blue [for sale]. Mk2 S/N 080000094 26GB blue)
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(list 6284, Mk1 S/N 00299 4GB blue [sold]. Mk2 S/N 080000094 20GB blue)