Privacy arises out of noise. You can find this in the most literal physical sense if you are holding a conversation in a busy restaurant. The people at the next table might overhear a few words, but no one else will hear anything because of the noise of other conversations. It is the same effect if you try to find yourself in a photograph of a crowd, perhaps at the beach or at a baseball game. Unless you are doing something highly distinctive, that cuts through the random patterns of the scene, you may be in the picture but hard to see. It is the same thing whenever you are part of a larger scene. To a surprising extent, when you want to just be part of the scene, you can hide in the noise. It is the “safety in numbers” that people talk about. If you try to cut through the noise and be noticed, you find that it is not as easy as it might seem.