A vast network of cameras goes on line today to provide security for the Winter Olympic Games in Vancouver and Whistler.

More than nine hundred cameras have been installed by the RCMP-led Olympic Integrated Security Unit, mostly covering Olympic venues.

Another one hundred cameras run by the City of Vancouver will be watching downtown streets.

The unprecedented deployment of electronic surveillance makes privacy watchdogs nervous and they have sought assurances from the authorities that the networks will be dismantled as soon as the Games are over.

Chantal Bernier, Canada's assistant privacy commissioner, says they have been promised the cameras will come down after the games.

And any recordings from the cameras can only be kept for a limited time unless they become evidence in a court case.