owning photographs is a very slippery slope. both side are equally valid in their points but then we need to remember that in both cases that we're talking about what could happen. Photo-synth hasn't been launched yet and the girl wasn't hurt by any means. Photo-synth has potential to be great and in some circumstances some one's private photos could be spread around the world.
as far as i'm concerned once you put your pictures online they're fair game to be used. I personally post plenty of my pictures online in the false hope that no one takes them. but i also turn down the resolution on my images when posting them so if people do use them they don't have the original image. I use google image for inspiration a ton. I rarely use it for projects because the pictures are a pain to work with and its copying and there by not really your work. companies don't really like that.