Graham Chainey (November 28) is quite right to be concerned about the amount of electronic surveillance today. However, he missed out some of the advantages.

As more than one police officer has discovered to his cost, the hidden camera stops Big Brother abusing his authority. The hidden camera has detected more than one crime.

Had the CCTV system been in use 20 years ago, the Yorkshire Ripper would not have gone undetected for so long.

CCTV also prevents miscarriages of justice. You cannot be convicted of a crime in one town if the cameras show you were somewhere else.

Equally, if the camera shows the crime being committed by a tall thin man, a short fat man cannot be accused.

-Stuart Bower, Hawkhurst Road, Brighton