[TwoforFun]

I honestly don't think they meant any harm. They fed the cat and probably felt bad the cat was wondering the streets that late. I would have a friendly talk and say that you don't want her to be fed so she can return home to eat.
You are lucky that you have neighbors that like animals as much as you do. There is nothing wrong with the cat being outside whats wrong it's the sick people lurching to do harm.