If the glasses can name people from your contacts, it's only one more step to name and recognize everyone it can including strangers, including showing any related info like reddit aliases (known and suspected), reputation in some reputation tracker or even criminal history, favorite alcoholic beverages and other interests to help with dating... enough people don't want that so they'll ban AR devices and punch out people they catch wearing them. This stuff is already going on to varying degrees, but mostly businesses watching people. Getting people watching people and really kicking off AR needs, besides the tech, more assurances that no one can tell you're watching. I agree there wouldn't be much adoption barrier for having to wear hardware, so many people wear glasses and sunglasses and hats all the time anyway, the barrier is just being inconspicuous.