noimmunity
scratch my niche
The thread doesn't address the 3rd party viewer because there is no ethical problem with them: if they don't like images of strangers (or find these particular images uninspiring), they simply do not have to look at them (no one is forcing anyone to stare at these images). There is no ethical dilemma involved and hence nothing significant to discuss on this score.
It doesn't take much attention to notice--in fact, to be forced to notice--the invasion of images into public space and the domination of what used to be called civil society by advertising. If anybody in this era still believes that the relation between image and viewer can be reduced to a question of free choice, it is either because of massive denial or self-interest.
I don't see the point in engaging this as an ethical question, when there are lots of other angles we could take, including economy, politics, and society. But what's so interesting to me is the way in which some people always want to individualize and privatize problems that obviously concern things having to do with public, social space.