Conspiracy Theories is about exactly what you would expect from the title and there are some crazy ones in the Shadowrun setting, some of which may actually even touch on the truth. It is a very useful book for fleshing out the world and the craziness that goes on in the background of the Shadowrun world.
Conspiracy Theories: A Shadowrun Sourcebook written by Jason M. Hardy, Jeff D. McLane, James Meiers, John Schmidt, Brandie Tarvin, Malik Toms, Michael Wich, Robert Wieland, Russell Zimmerman and published by Catalyst Game Labs.
Sea of Stars RPG Design Journal 