I agree on the whole no vengeance part but just walking away and saying nothing also has consequences. I personally tend to write people off in my head and just distance myself from them. I see them socially in groups but no interaction is initiated from my side in terms of making the effort to connect with them especially. If help is asked for I will not say no, but then I notice these people always give you the short end of the stick. So I Suppose it's hard to find that balance of not hurting them, trying to make them aware of their behavior without driving them over the edge. But i do feel they need to be made aware of their behavior if it is very harmful or hurtful to others!