Good on Google to attempt to combat rampant bad manners using their tech. Unfortunately I don't think it'll work. Tact and social graces have been dead since long before Google even existed
Bad to all you brain-dead cave dwellers who are so damn hung up on this piece of tech somehow taking your picture that you think physical violence is ok. Here's a news flash for you bright sparks:
1. Nobody in the public sphere gives a fuck about you. Not me, not them, not anybody. Don't believe me? Go walk down a sidewalk in Manhattan and start randomly complaining to passers by about oh, cameras or something.
2. You're already on quite a few cameras, whether you're in public or on private property. Lots of them are manned by underpaid staff whose only bright spot to the day is uploading footage they find amusing to social media sites.
3. You assaulting someone who happens to possess a piece of hardware you don't like does, in fact, make you a criminal in a whole lot of jurisdictions. As opposed to your glass wearing nemesis, whose mere inclusion of you in the background of his photo of something else is either not typically culpable, or at the most a slap on the wrist.
I personally have a use case that I'd like to try Glass out for. It does involve wearing them in public. However, I do possess sufficient tact to remove them when interacting with someone. Were I to be assaulted for possessing them, or threatened with such, my response would be very much the same as to an attempted mugger. Being that I do reside in a country with rather widespread firearms ownership, engaging in this sort of self expression could earn you a well deserved perforation.
So far it seems as if the number of assholes wearing Glass are vastly outnumbered by the assholes who consider physically assaulting someone for such to be acceptable.