Whilst not the case in this instance, there appears to be a large number of people who do not understand the difference between "Standby" and "Off". We encounter this problem on a regular basis in our hospital. We have a mobile phone detector which informs us when someone has entered our unit with one switched on. The number of times this happens because people do not understand that "Swtiched off" means exactly that - OFF is unbelievable, they believe that "standby" means the phone is off and can take quite some convincing otherwise. We have large, clear notices on our doors and in spite of this some people simply just forget or ignore the notices.