@CaRDiaK:There's something different regarding Google Glass.

Most of these phones with camera would be put into bag/packet if you're not using it, but with Google Glass you're wearing it even if you switch it off and use it as plain glasses.

If someone managed to have some malicious software installed, chances are you'll be recording something without knowing it yourself. (Remember the case where people being able to take pictures while your phone is locked, and reconstruct 3D model of your room and workplace based on those photos?)