The Feldman Boys
The Feldman Boys are a "mob" of Venutian prisoners primarily based on Lewis Orbital Mining Platform, united by Dokko Feldman. They are the largest organized group of prisoners on Lewis Platform, and control all the resources and "wealth" there.
Dokko Feldman has created a network of influence among the prisoners of Venus by making deals with the leaders smaller "gangs" on both platforms (which was pretty easy, since he controls the incoming Mars Coalition supply shipments). While the individual gangs that make up the Feldman Boys mostly do whatever they want, they all ultimately answer to Dokko.