Disclaimer: I could probably be classified as a Google fanboy, but I do not own Google Glass.
I think these types of arguments are silly, because they take an already existing issue and then pretend that Glass is the only cause. Seriously, look around the next time you're in a restaurant. There are always people pulling out their cell phones to snap a picture of their food or friends, and of course people they don't know will be in the background of the photos. This is really what you're worried about with Glass? This already happens.
Do you think that the problem will be worse with Glass? If so, why? And how much worse?