When pictures are legal

I've been trying to figure out when someone can force you to take a picture or video down off the net. Every one has an opinion, but no one has the facts. Here is what it sounds like to me after a couple hours Googling.

• If the person has an expectation of privacy, they can sue you to get the media taken down.
• If the person has no expectation of privacy, they can sue you to get the media taken down.

Clear as mud?

Here are some details that may or may not be true. I can't figure it out.

• If your feet are on public property like a public road or sidewalk you can snap or film away. People have little to say about what is visible from the road or other public access.
• If you use some kind of technology to, for example, look through walls then you are violating the rules.
• If you take excessive media of someone that may be harassment even if it is by the letter of the law.
  
• Bridges and some public transportation are illegal because of terrorism laws.
• If you are on private property (like TRF)
• The property owner has to post signs telling you clearly what you can and cannot take media of. The precedent of letting and indeed encouraging people to take pictures has been set. I would imagine the camp grounds and internal portions of the park are considered public accessible land for purposes of media.
• The Patron's camping and the inside of every shop is a matter of posting signs and individual shop rules.
• Inside a closed up tent or car is about as much expectation of privacy as one can get out there.
  

Like I said, don't take any of this as gospel. I have no idea how close I am to the truth. It doesn't matter what you do, if someone gets pissed at you about media you post, you will either have to give in or get a lawyer.