The people who did this are not representative of the Iraqi people as a whole, just as the many, many *American* soldiers who tortured and abused many *many* Iraqi prisoners are not representative of our country as a whole.
We have goals in Iraq, and we have killed men, women, and
children to achieve those goals. They have goals as well, (namely ending the US occupation of Iraq) and is it any surprise that they will kill in an attempt to achieve them?
Regardless of which side has the "correct" ideals and morals, atrocities have been committed by both.
Personally I feel that the most inhumane thing any individual can do is value people of one nationality, race, religion, sex, etc. over another.