As a Cleveland Cavaliers fan, I have a special hate for the Heat. That being said..... It may be legal to take those pictures, but this is an etiquette board and I find it rude to take a picture of anyone without their permission. If I were on vacation and taking a picture of say a monument, and other tourists happened to be in the picture, I wouldn't feel the need to ask their permission or find it rude, but I would not go up to a person and specifically take their picture without asking. When I was in Williamsburg, I asked the costomed interpreters if it was OK to take their pictures. Maybe not strictly necessary, but it seemed like the nice thing to fo.