Google Glass, a high-tech pair of spectacles with in-built hands- free video camera and internet access, has already raised privacy fears because it can record video far less conspicuously than a handheld device and could make it difficult for people to know when they are on camera.

It is set to be the next big thing for gadget lovers everywhere. But users of Google Glass, a high-tech pair of spectacles with in-built hands-free video camera and internet access, are being given some basic advice – take them off when visiting public conveniences.