At Officer Basic training at Ft. Sill we were taught the official line that Willie Pete should only be used against equipment and supplies - never people. It was considered a violation of the rules of war to use WP on troop targets. However, unofficially, our instructor pointed out that it was ok to use WP on the weapons and belts and uniforms the people were wearing - that was equipment too.
It's not the use of WP that bothers me about these reports but that WP was used on civilians. Our military in Iraq could be indiscriminately firing on civilians - including the use of WP. That's the outrage that should be investigated and stopped.