Malleus Maleficarum

One faction of the city is openly controlled by a coven of hags, who have established a network for protection and influence peddling. The people who deal regularly with the hags trade tips and secrets to getting an acceptable bargain out of the coven. The city tolerates the coven because the hags wage magical war against the city's common enemies, the other factions are perceived as even more corrupt or demanding, the hags create opportunities for advancement that do not regularly present themselves elsewhere, and -- surprisingly -- the hags seem to follow rules that even they can't break.