Bluetooth headsets used outside of the office/car says to people that my phone calls are so important that at any time I am likely to ignore any social protocol (train, toilet, bank, whatever) and take this call.
Google glasses say to people that at any time I am recording every move that person makes and potentially (a) putting it on Youtube, (b) laughing about it with my friends, (c) handing it over to the police etc.
It is unquestionably for douchebags.