What would you do in this situation...?

I just found out that someone at work is about to get screwed over in a big way that will set a precedent for this type of thing to happen to others. The person who told this to me said that we should do nothing, not even warn the person, because it does not directly affect us. But, it could in the future because, as I said, it will set a precedent. So I think we should at least warn the person, so they will be careful and, hopefully, the people trying to screw her over will not succeed and my job will be safe as well. If they can do it to her, they can do it to anybody, right? But, I am getting negativity from all sides, even though my reasoning is sound and logical. So, I want to know what any of you would do. Serious answers only, please.