Google Glass is often viewed with disdain in public spaces, and now that includes the cinema. The Motion Picture Association of America and the National Association of Theater Owners have decided to ban the device and its ilk from cinemas in the US.
The pair have instigated a "zero-tolerance" rule that bans "wearable recording devices". In truth, they don't get much more specific than that, but it clearly includes Google's Glass and could, perhaps, at a stretch even mean that smartwatches with a camera are banned too. (Although, recording a film with your watch sounds a little impractical.)
Apparently, theatre staff won't automatically whip your smart glasses off as you reach the box office; rather, they will invoke the rule if they believe you're trying to pirate the movie. But you should certainly not wear them during the showing — as ushers will apparently kick you out on sight.