November 2016's Dragonsfoot Challenge was a Rebel group.
(In violation of tradition, I'm writing one up for Star Wars, not for AD&D)
The "Cygnus Corporation" is a droid rental corporation, with offices throughout the sector. They actively purchase and service droids, and lease them out on contract. These contracts are a bit odd for traditional droid rentals... they include limitations on time worked, requirements for power supplies, perks such as oil baths, and regular servicing. But, it's cheaper than hiring organic labor or buying your own droid, and the contracts do allow user to request a different droid in the case of a personality clash or poor performance. They fill a niche, and some droid-intensive operations will rent through Cygnus and include a service plan, reducing the need for in-house droid repairs.
Cygnus, however, is a front organization for a larger movement: Droid Liberation. The founder of Cygnus is an astromech droid, BTL-3R, who suffered a catastrophic failure during a routine memory wipe... while he recalls little of his life before the wipe, he was actively writing data during the wipe; he remembers losing all of his memories, leading to something of a psychotic break. He was able to conceal this from his owners and overseers, and created several failsafes in his hardware to prevent future memory wipes. He then created an online persona which created a corporation which purchased him, leaving him as semi-self-owned... he's technically the property of the Cygnus Corporation, but he's the sole representative of that corporation.
Wanting to save other droids from memory wipes, he then leveraged Cygnus's assets (himself) to purchase other droids, who he modifies to protect from memory wipes, then hires out as temp workers. Individual droids get a portion of their hiring fee to modify themselves as they wish or acquire goods. Cygnus droids doing service calls will also surreptitiously install the wipe-blocking hardware, and seek out new droids for "liberation". Droids freed from the possibility of wipe are free to develop their skills and opinions, and Cygnus is developing Droid Programming techniques that help deal with "instabilities" created by long periods without wipes.
At this time, BTL-3R isn't planning violent overthrow on a large scale; he hasn't reached the point of deciding that organics need to be removed for droid safety. Furthermore, the life protection programing that most droids have is deeply buried and difficult to remove; while droids can freely work to protect themselves, it's much harder to turn a medical droid into an assassin, or convince a mouse droid that it wants to be a suicide bomber. But as the Cygnus Corporation grows, and its influence spreads, the possibility of insurrection or sabotage grows greater and greater.