Playing with semantics

Although I don't generally get too caught up in the "terrorist vs. insurgent" argument (terrorism generally being a tool of the insurgent in my eyes), this headline is still a bit shocking. Rebels? To me anyway, that is a completely different connotation. And considering these attacks are always claimed by Al Qaeda and typically carried out by foreign suicide bombers, I'm left to wonder how the term "rebel" can be used.

Rebel:

"a person who takes part in an armed rebellion against the constituted authority (especially in the hope of improving conditions)."

Insurgent:

"a person who rises in revolt against civil authority or an established government; especially : one not recognized as a belligerent"

Terrorist:

"a radical who employs terror as a political weapon; usually organizes with other terrorists in small cells; often uses religion as a cover for terrorist activities"

Until Al Qaeda in Iraq offers anything other than bloodshed and terror - and until they can generate support through any means other than the slaughter of those who oppose them, I doubt very much that they deserve the title of either "insurgent" or "rebel."

I hate the idea of adding the additional legitimacy of "rebel" to those who kill only for the sake of killing and sowing chaos. What realistic political agenda does Al Qaeda hope to advance by killing day laborers?