My bet is on cannibals too. While we have only seen the perimeter, people seem quite sparse for a supposed sanctuary for all. And meat... Yah, as awesome as a welcome burger sounds; Giant Cooker as part of our very first scene seems cannibal cult ominous.
Anyone else think gang leader was the one that planted the rabbit? Guy beaten to death certainly ties up that loose end. Also, I don't know much about hunting and prep... but just storing half a rabbit in your bag o'stuff seems like the way to get terrible terrible diseases.