So I purchased my first Dslr camera a few weeks ago. A nikon d3100. So far I'm loving it and having lots of fun experimenting and getting to know it. I took a quick 2 day class to get a footing. Anyway, since the weather was nice this past weekend dh & I decided to go play in center city Philadelphia. I of course take the new camera to get some practice. Problem was my dh kept warning me about taking pictures of people. For example we were at the liberty bell complex and here I am clicking away and he says "be careful with that thing, people may not want you taking their pictures". Then I was trying to take some pictures of moving cars to learn about the shutter speed setting. Once again he thought it was a bad idea? Anyhoo, is there some proper picture taking etiquette that I'm missing. Previously I've only taken shots on vacation, like at disneyworld and it seems every one has a camera there. Does anyone simply grab their camera and take pictures in their neighborhood?