In Herbert's fiction, sometime in the far future, government becomes terrifyingly efficient. Red tape no longer exists: laws are conceived of, passed, funded, and executed within hours, rather than months. The bureaucratic machinery becomes a juggernaut, rolling over human concerns and welfare with terrible speed, jerking the universe of sentients one way, then another, threatening to destroy everything in a fit of spastic reactions. In short, the speed of government goes beyond sentient control ... Founded by the mysterious "Five Ears" of unknown species, BuSab began as a terrorist organization whose sole purpose was to frustrate the workings of government in order to give sentients a chance to reflect upon changes and deal with them. Having saved sentiency from its government, BuSab was officially recognized as a necessary check on the power of government. It provides a natural (and lucrative) outlet for society's regular crop of troublemakers, who must be countered by society's regular crop of "do-gooders".
FWIW, I find Dune and many other classics of sci-fi (extended to film, TV and videogames) so compelling because it's a solid story built on the foundation of a carefully imagined and visualized universe ... down to the political power structure. There are a few other universes worlds that also hold up, despite some poor sequels and side projects ... Urth, LOTR, Star Wars, Half-life, etc.