Principalities and powers
|Light iron-age reading|
|Gabbin' with God|
6:11 Put on the whole armour of God, that ye may be able to stand against the wiles of the devil.
6:12 For we wrestle not against flesh and blood, but against principalities, against powers, against the rulers of the darkness of this world, against spiritual wickedness in high places.
6:13 Wherefore take unto you the whole armour of God, that ye may be able to withstand in the evil day, and having done all, to stand.
This is taken by certain Christian sects (especially King James only sects) to mean that they are in a literal struggle against a group of actual evil spirits who compose the Principalities and Powers.
Principalities can also be defined as a political territory under the jurisdiction of a prince. Therefore some interpret the verses to mean that the world is actually controlled by a cadre of demon princes, each of whom control a certain region or people.
The Principalities and Powers are also the 7th and 6th rankings of angels, respectively, just to make things more confusing (since some believe all demons are fallen angels, one might guess the ones referred to derive from these rankings).
 The Inevitable Implication
This verse is a lynchpin in the mindset of many hardcore Christians who are also conspiracy theorists. The idea that the world is run by powerful people, secret organizations or aliens pales in comparison to the concept of a world directly ruled by demons who are both all powerful and literally invisible. It also has a nice military flavor to it, with the whole "armor of God" thing going on. It makes people feel like they're war heroes, except instead of dodging bullets, fighting for their lives and surviving in hostile terrain they fight by believing and praying and their enemies are invisible.
It's a universally applicable ad hominem attack that can be applied to any government personality, branch or action. Even Glenn Beck has claimed that his opponents were principalities and powers while he was still pushing his badly researched Boston Marathon Bombing theories.
 See also