Baghdad Residents Kill Three Militants?

Recently The Guardian printed an article about an event in Iraq with the headline Baghdad Residents Kill Three Militants. It read just like any other article in The Guardian covering Iraq. You will find the words militant, insurgent and gunmen used throughout the article -- just like any other article about Iraq in The Guardian. The problem is that when you read the article, you realize that it is not about militants, insurgents or gunmen but is about terrorists. Here are the first three paragraphs of the article which I have "corrected" to be more accurate:

BAGHDAD, Iraq (AP) - Shopkeepers and residents on one of Baghdad's main streets pulled out their own guns Tuesday and killed three insurgents terrorists when hooded men began shooting at passers-by, giving a rare victory to civilians increasingly frustrated by the violence bleeding Iraq.

The clash in the capital's southern Doura neighborhood erupted when militants terrorists in three cars sprayed bullets at shoppers. Three people - a man, a woman and a child - were wounded.

The motive was unclear, but there have been previous attacks in the ethnically mixed neighborhood. Earlier in the day, gunmen terrorists in the same quarter killed a policeman as he drove to work, police Lt. Col. Hafidh Al-Ghrayri said.

This article is a good example of bias in certain media outlets and news agencies. While the writers and editors may believe that they are being impartial and avoiding any political meaning in their terminology, they in fact are committing a political act. People that are deliberately "shooting at passers-by" and that "sprayed bullets at shoppers" are terrorists. Not militants, not insurgents, not gunmen -- terrorists!

Unfortunately, using misleading definitions and terminology is also a common practice at Reuters, the BBC, AP, The New York Times and other major media outlets. I know that journalists are taught ethical standards, but what I don't understand is why don't they follow them?