Other industry experts take a more serious tack, pointing out the potential for misuse because Glass can record video far less conspicuously than a handheld device.
Glass also has won many fans. Google and some early users maintain that privacy fears are overblown. As with traditional video cameras, a tiny light blinks on to let people know when it is recording.
Several Glass wearers at the developers conference said they whip the device off in inappropriate situations, such as in gym locker rooms or work meetings. Michael Evans, a Web developer from Washington, D.C., attending the Google conference, said he removed his Glass when he went to the movies, even though the device would be ill-suited for recording a feature-length film.
"I just figured I don't want to be the first guy kicked out of the movies," he said.
A stamp-sized electronic screen mounted on the left side of a pair of eyeglass frames, Glass can record video, access email, provide turn-by-turn driving directions and retrieve info from the Web by connecting wirelessly to a user's cell phone.
"Criticisms are inevitably from people who are afraid of change or who have not figured out that there will be an adaptation of society to it," he said.
Schmidt acknowledged that there are certain places where Glass will not be appropriate but that he believed new rules of social etiquette will coalesce over time. Firstenberg said it will take time for all sides to get comfortable with the new technology.