The difference is that taking photos or filming with a mobile phone or digital camera is an explicit action that is usually obvious to the people being filmed.

The difference is that taking photos or filming with a mobile phone or digital camera is an explicit action that is usually obvious to the people being filmed. With always-on gadgets like Google Glass, you can never be sure whether the wearer is recording you or not. I guess that some people wearing Google Glass might not even be aware that they are violating someone else's right to privacy. Therefore, it is certainly helpful to explicitly declare one's place a 'no recording' zone - if only to avoid events such as [1]. [1] http://eyetap.blogspot.de/2012/07/physical-assault-by-mcdonalds-for.html http://eyetap.blogspot.de/2012/07/physical-assault-by-mcdona...