Yesterday morning, as I walked from Penn Station to the New York Public Library for the NYG&B's program on the 1940 Census (at which I was speaking), I was probably photographed a dozen times, mostly by Asian, Italian or South American tourists. When I walked back to the train station later that afternoon, the same thing happened.
Actually, it wasn't me that was being photographed; it was either a NYC landmark or some kind of touristy "group shot."
I just happened to be in the general area that the person with the camera was focusing. I was, in effect, the "accidental passer-by." As a result, I ended up in lots of pictures that would eventually come to rest in places as diverse as Osaka, Firenze or Montevideo.
Which, of course, raises an interesting question. How many of us are accidental subjects (albeit background players) of other people's photos, simply because of where we happen to be walking or standing?