Who'll know unless you publish the image without change? As is often the case, it's not the taking of the picture that's causing the problems, but the publishing.
If you were indeed photographing the building and didn't notice the person, there shouldn't be any problems (shouldn't be, not saying that there won't be any...)
Now, if you were shooting a panorama of the building with a 500mm and you caught the star living on the 5th floor in her birthday suit, that's a different case.
Isn't it legal to take pictures in public areas? And if there's surveillance camera's in private areas, there's signs saying so. I think the defense would be rather weak.What if a defendent in a trial says the police cannot use surveillance pictures because they breach his right to privacy?
If the pictures in question were taken in other circumstances, doesn't that require a warrant signed by a judge?
I agree that the artist crossed the line here. Not in taking the pictures perhaps (although I'm not too sure there), but certainly in publishing them w/o permission.I personally feel the artist crossed a line but perhaps we need to think about where that line actually is.
There is an old saying about people in glass houses not throwing stones but perhaps we should add that they should get net curtains as well.
And having curtains in front of the large windows all the time defeats the idea of having those large windows in the first place...
Then again, engaging in activities you'd rather not have observed, I'd stay away from large windows facing the street (or the neighbours).
I wouldn't take pictures in this situation, and even less publish them in any form. But unless he had to use a long tele lens, or was fairly high up (2nd floor or above?),
I'm not sure what he did is in any way illegal. We get back again to the notion of 'reasonable expectation of privacy': ground floor rooms with such windows facing
a public area would have NO expectation of privacy, unless there were curtains...