I’ve know a number of people to be threatened about their act of taking pictures as being illegal. Turns out taking pictures is a lot more legal then most people realized. Basically, if you are taking a picture of something in public, then it is legal. So you can go to the mall with your camera and take pictures, or take pictures of a building.
Andrew Kantor did some great research on when and what it is legal to photograph, as well as when and what it is legal to publish. Your biggest threat is a civil suit, or being charged with trespassing while taking the picture.
Just remember, neither Andrew nor myself are lawyers, and this is not legal advice.