BPA's membership size is unknown, as is the recruiting procedure. Latest estimates are that less than 350 operatives per planet are active at any given time.
The BPA has a division in Terra Novam.
The Bureau's official buisness is Foreign Relations, Internal Affairs and Education, but this is mostly a front.
BPA's real job is the elimination of all dissent, be it political, religious or even liberal thought, though they serve myriad other purposes as well. It is suspected that BPA has operatives in the boards of the larger companies and even holds seats in ANSOC's Inner Party, though this has neither been confirmed nor denied.
Usually, when BPA confirms a dissenter, (s)he isn't killed, but brainwashed, regardless of the time and resources poured into this. Only the most dangerous dissenters are executed, and then always in secret.
Another task of BPA is the whitewashing of history, constantly altering photographs, newspapers, television and radio broadcasts, books and songs, removing all names and references to dissenters and replacing them with more unknown persons, or erasing them outright. Continuing the same line of thought, alterations are made to ensure that no information is available about other forms of government and other styles of life. These revisions are never done, as the Emperor may change opinions from one day to the next, and whatever the Emperor says is undeniably the truth.
BPA is also the organization responisble for Indoctrintion. (see: Indoctrination)
Venture Group is the Bureau's military arm. Venture Group operates from an unknown number of the BPA-exclusive Venture class Battle Cruiser, a ship specifically designed to combat and destroy other Terran ships instead of aliens, though they still pack a heavy punch against foreign enemies.
Also housed on these ships are BPA's ground forces, as well as a small army's worth field agents and operatives who specialize in abduction and liquidation.
BPA non-political Branches (WIP)
SateSec (State Security)
DSI-A (Department of Secret Intelligence)
DSI-A is the Empire's source of intelligence on foreign powers. For obvious reasons they cannot be summarized.
DSI-B (Department of Special Intelligence)
DSI-C (Department of Scientific Intelligence)