Are you surprised? With pictures on the TV and in the papers every day of the violence such as a bomb dropped (perfectly) throgh the center of a Red Cross vehicle there will be trouble. There are loonies on both sides. Get used to it, it ain't going away anytime soon.
This is another sterling example of the benefit of not being able to protect yourself at work. An enviornment where people are disarmed provides easy targets for an idiot like this. If an idiot like this was blown away by an armed worker it would go a long way to stopping such acts.