Maybe "current case law", for the state you must live in, (if that's true, leave immediately). Try that in my state and you are going to get a very nasty wake up call. After the home owner or his neighbors beat you senseless, Law Enforcement will be taking you to jail. If you decide to get feisty and push your belief of your "right to video tape someone in their own backyard", you WILL be going to the State Mental Hospital for a 30 day court ordered mental health evaluation. Get feisty while you are there, and that will be your new mailing address.
Oh, by the way; our Castle Doctrine allows a home owner, (or neighbor), to shoot you to death if they felt you were behaving in a "threatening manner". You will also be going to jail here for "creating apprehension". We have several more rabbits to pull out of our legal hat too, for someone that wants to get cute.