Yes, I do agree that having lights shine all night long in the back of someones house is not a considerate thing to do. But, I hear quite a bit or anger and rage in the original post. If you went over there to "tell them off", it just is not a good thing. You are trying to SAVE your friend. Instead your negative energy will only HARM your friend. Is this how you generally handle things? Confrontation might be your style. I don't know this nor do I know you.
I would start by having your "friends" visit them and introduce themselves. You may be able to get to the reason WHY they have these lights installed. Once you know the reason, your "friend" can weave the light issue into the conversation. I would BUTT out of your friend's situation. It's her deal there!
