Right now the primary use case of the Google Glasses is as an always-on video camera. Now most people (including myself) don't appreciate being filmed without permission and there are plenty of situations where people could be filmed committing illegal acts.
So I can guarantee you that injury is going to occur at some point and especially in the US a not insignificant chance of being shot.
So I can guarantee you that injury is going to occur at some point and especially in the US a not insignificant chance of being shot.