Longe Optical President Jeff Ostermann explains how Google Glass operates, in Fort Wayne, Ind. (Cathie Rowand/Journal-Gazette via AP)

Get ready to hear "Please silence your mobile phones -- and take off your Google Glass" in a movie theater near you.

The Motion Picture Association of America and an industry group representing the owners of 32,000 moving screens across the United States announced Wednesday that they have updated their anti-theft policy banning recording devices to include "wearable tech," such as Google Glass.

The new guidelines read: "The National Association of Theatre Owners (NATO) and the Motion Picture Association of America (MPAA) have a long history of welcoming technological advances and recognize the strong consumer interest in smart phones and wearable 'intelligent' devices. As part of our continued efforts to ensure movies are not recorded in theaters, however, we maintain a zero-tolerance policy toward using any recording device while movies are being shown."

"As has been our long-standing policy, all phones must be silenced and other recording devices, including wearable devices, must be turned off and put away at show time," italics added to indicate the policy change. "Individuals who fail or refuse to put the recording devices away may be asked to leave. If theater managers have indications that illegal recording activity is taking place, they will alert law enforcement authorities when appropriate, who will determine what further action should be taken."

Movie theaters aren't the only ones snubbing Google Glass. Some bars and restaurants have moved to ban Google Glass out of concerns for privacy and general unsociability. But movie theaters have another concern: that the films they're showing are being recorded and pirate copies of them distributed worldwide. In January, an Ohio man said that he was thrown out of a movie theater for wearing Google Glass.

The guidelines, says Kate Bedingfield, vice president of corporate communications at the Motion Picture Association, are best practices for theater owners and not formally binding. "How they enforce it is certainly at their discretion," she said. But the policy, says Bedingfield, naturally follows from the principle that once movie goers enter the theater, "devices must be turned off and stowed."

But that, perhaps, it isn't as straightforward as it seems. Leaving aside that someone might want to use Google Glass to experience a real-time annotated version of a new film, the trend toward making wearable tech fit more seamlessly in our lives and our bodies makes policing its presence more difficult. Must you take off your Apple Watch in a theater should it get recording capabilities? Stay tuned.