A more likely consequence of camera surveillance is that crime and undesirable conduct are displaced into neighbouring areas once cameras are installed in a target location. Statistics are rarely kept on displacement, and it is hard to account for in statistical analyses. When claims are made about deterrent effects they may be a result of displacement. Whether in a downtown location or on a university campus, cameras push targeted activities out of sight. In San Francisco, a study by the City and the University of California Berkeley found violent crime decreased within 250 metres of ‘open-street’ surveillance cameras, but increased beyond 250 metres. Sometimes cameras are used by police and private security precisely because of the displacement effect, which then invites new cameras to be set up elsewhere while neither the problematic activity nor its root causes are addressed.