Cammalu, I have done many, many kinds of photography in my lengthy career including forensic, surveillance, and I've shot for newspapers and magazines..
There are many, many ways to accomplish getting the photo, and yes I've taken photos of folks who weren't happy about it... for a variety of reasons. And yes, I've photographed people who have DEMANDED in no uncertain terms that I not photograph them, and then DEMANDED that I give them the film. I have always tried to be as inconspicuous and considerate as I can, but I've actually had folks who were incidental to and walking through a shoot threaten me for taking their photo when it was they who photo-bombed the shot.
I've done work on Indian Reservations, and literally survived the assignment (a long story.)
And there are very famous photographers who, if they violated MY personal space in their own inimitable fashion would likely end up on the ground in an arm-bar come-along because I'd thought they were attacking me.
Bruce Gilden comes immediately to mind. His style is obnoxious and, to my way of thinking, dangerous. He certainly has a right to make images, but he doesn't have the right to make folks fear for their physical safety while he's doing it.
But what I'm saying is that if folks expect privacy in public, they're not going to find it, and it's not reasonable to expect it. I just don't understand what has led folks to believe that they have some kind of
right that they
shouldn't be photographed in public.