David Haines was

murdered. He was brutally murdered after being humiliated in the most public way possible - on the internet.
The internet has changed war. You can do immense harm from the safety of your laptop in an anonymous setting. You can send out the most vile, menacing and outrageous messages to the world without moving from your chair. You can "encourage" young men - and even young women - to believe in martyrdom through violent murder-suicide with a reward of virgins in heaven. Of course you won't send your own children to do these despicable acts. They will be somebody else's children.
Well, David Haines was somebody else's child too. Unlike those being encouraged to indulge in the ultimately selfish act of murder-suicide or the games of murder of innocent children who happen to believe something different, David Haines was genuinely trying to help other people.
David Haines, like many aid workers I know and admire was taking risks to help others. He was not out there for the fun of it. Oh yes, there might be the occasional adrenalin rush - of relief -  but it was not something he looked for. Aid workers like David Haines go in with a purpose and that purpose is to help, genuinely help.
I don't know precisely what David Haines did. I never had any contact with him but I know what people like him do. Too many of them have to put their lives on the line everyday. They have to take risks to make sure that the limited food and shelter and even more limited medical supplies actually get in there and get distributed. More often than not it is chaos and they have to do their best to handle that chaos. All too often it is violent and they have to handle that as well.
The men - and they are mostly men - with guns don't care. The man who so brutally and violently murdered David Haines was almost certainly one of his fellow countrymen. He undoubtedly enjoys being violent. Murder almost certainly comes easily to him.
But, he hides behind a balaclava just as those who send out the other vile material hide behind their laptops and the internet. David Haines and his fellow aid workers, the ones I know and trust and admire, are brave people. Their killers are cowards.