Jonathon, you are correct. The basis of this law is to protect people's private lives. But, in this instance, the piano player was playing in public, so he could not claim that a picture was invading his private life. Still, had he signalled his opposition, I would have deleted the picture. On the contrary, he "played along" to the mutliple photographers there (it was a Meetup), some of whom got much, much closer to him than I did (wimp!)