I was doing a removal for a lady this morning and things were going fine and as I was getting off the bucket truck the lady asked if I could remove a low hanging limb from the neighbor's silver maple. I did not think too much of it and it was a pretty simple pruning. The limb was hanging down in her driveway. I thought sure, no problem. I know she has the right to remove the limb from her property and as long as I leave a proper pruning cut we would be fine. I look over at the neighbor 2 houses away and he is snapping pictures of me and did not think to much of it. We proceed to prune the limb and as I am making my final cut the guy comes over (he owns both houses...next door to my customer and the next one) and wants to know what we are doing. I told him I am pruning the limb so the neighbor does not have to deal with it in her driveway. We exchange thoughts and he disagrees with her rights. I finish the cut and come down from the bucket. At this point I did not think much of it and my customer was well within her rights and I did a good pruning cut (no harm to the tree). I walk around the corner to go talk to the guy and discuss potential hazards in the tree (broken limb, poorly installed cable, multiple cavitites). I know the guy from a previous working relationship and he is a pretty nice guy. I come around the corner and the police are waiting for me. It turns out the neighbors don't get along and I was caught in the middle. I explain to the officer what we were doing and said I would stop what we are doing until the property owners can work it out. I pointed out we were doing the right thing and the tree has hazards in the tree over the property line. I also told the guy who owns the tree what the hazards are in the tree and if she wants to proceed with pruning the tree back over the property line, she has the right to do so at her expense. I also told the guy of the broken limb in the tree and if something were to happen he may be liable due to neglect as he is now aware of the situation with the tree. I realize I should have made an attempt to talk with the owner of the tree before we did anything. I know now to do that in the future. My question....how do you guys handle these situations? Is there any literature available to provide to homeowners that will spell out both sides rights?