User blog comment:Zathronas/Speculative author: What is Cinder's plan?/@comment-16241789-20140803233812

Well, I do think Cinder was on a team in the past, and that something happend to that team that Cinder blames figures of authority for (probably Ozpin), and now she's got a vendetta against him and his school. Either that, or, as you said, someone close to her was hurt or killed because of a mistake Ozpin made. But if that were the case, she'd probably have a vendetta against whatever was responsible for what happened to her old team (or friend), which in this case would most likely be the Grimm. With that in mind, I feel that while she's planning to fulfill her vendetta against Ozpin and Beacon (assuming she has one), she's also trying to spur the world into evolving through conflict (like the Shadows, for anyone who's seem Babylon 5) in order to get everyone ready to fight the Grimm, which she believes are a massive threat.

That's one theory, at least. Some of the things that have happened so far (Cinder infiltrating Beacon, which suggests that Ozpin doesn't know her, otherwise she would have stayed away unless he doesn't know what she looks like) work against it, but I still think it's pretty likely. I guess we'll just have to see what happens.