I'm at the GPN16 at this very moment and I was amazed by one event which tool place while beeing outside and hacking on some Python code.
A guy came to me and told me that he just took a nice picture of me. He showed me the picture, which was indeed really nice, and asked whether this is okay or whether he should delete it.
I love that! He asked for permission, which is really awesome. Of course he did after he took the photo, but that's okay with me, as he took it with a camera and not an Android or Apple device or something like this, where I would assume instant sync to the cloud or something like that.
I really like beeing asked about this. I told him that I don't like beeing photographed and he deleted it instantly and also explained what he was doing (“Look here, Delete –> 'Delete this photo?' –> 'Yes' –> Photo deleted”).