Originally Posted by the_13th_redneck
Actually the irregular fighters are not protected under any convention.
Which is why it's not technically illegal.
I was pretty sure that the rules were quite specific, check section 1, Chapter 1, Article 3 (it's not too far to scroll). http://www.icrc.org/ihl.nsf/FULL/195
Still it's best to only apply the rules of decency and humanity to those that you like. After all, if a government is willing to pay a bounty to have anyone picked up off of the streets, kidnapped, tortured & incarcerated, without trial - they can't be all bad, can they?
Do unto others as you would have them do unto you.