My point is that if cameras are not outlawed, then you can be photographed in public by accident, just because you happened to walk into a shot or happened to be in the background when some tourists wanted to photograph something. There's a difference between you can't photograph me while I'm in public and you can't harass me. Its not the act of walking in the same direction and in close proximity to the person that makes following them in public stalking, so you don't need to ban public photography of other people in order to prevent them form being surveilled, recorded and stalked.

I guess that I find the idea that you should expect privacy when in a public space kind of strange (its right there in the word: public), but that doesn't mean that I think its ok for someone to follow you around recording you (but not because of the actual act of being recorded, but rather because of the targeted nature).

Similarly, I think passive recording (ie non-targeted surveillance) of public spaces should be allowed in and of itself, but that its the use that dictates whether its abusive or not (ie if its done so that people can be identified, then that seems similar to me to following someone around, but if its done for the backdrop of a movie or art project, or its done to study foot traffic on a street.. basically there are many reasons which aren't abusive).