In his first city, cameras were on every vantage point. Only the authorities could access them. Crime fell, but the city's inhabitants knew that the police could monitor their behaviour and record their arguments against the status quo.

Brin's second city looked much like the first. It, too, had cameras on every vantage point. All citizens could access them via devices on their wristwatches, however. (He could not predict the sophistication of the modern mobile phone.) A woman walking home could check that no one was lurking behind a corner. A man late for a date could check if his girlfriend was still waiting for him. When the police arrest a suspect they do so with meticulous attention to his rights because they know that unknown eyes might be monitoring them.

The conceit of our age is that we live in Brin's information-sharing city – an understandable conceit because in many respects we do. I do not need to go through the thousands of ways in which new contacts and reserves of information have opened up. Given the speed of change, I am not surprised that the utopianism of the 1990s is still with us. The Australian philosopher Peter Singer said recently that the web was allowing a modern version of Jeremy Bentham's Panopticon. Like Bentham, Singer is a utilitarian. He thus saw nothing sinister in Bentham's vision of a prison where a few guards could see all the cells from a watchtower at the centre of a circular jail. Rather, he welcomed the constant monitoring proliferation of cameras, webcams, mobiles and data collection allowed. I am still shocked by the speed with which the British, a people once renowned for their reserve, allowed their country to become home to more CCTV cameras per square mile than anywhere else in the free world.

Singer sees the cameras as grounds for hope. Surveillance may make us more "honest and transparent", as we realise that our lies could be exposed, he said. It could make us more altruistic as the public charity of others shames us into giving. The authorities may act to a higher standard too. They would know that whistle-blowers could give their shady secrets to Wikileaks, hand them to the press or post them online, and adjust their conduct accordingly. Others can find out more about us, but we can find out more about them. That's the deal for the 21st century. Like so many others, Singer would have done better to remember the authoritarian possibilities of the internet and recall that Bentham's first concern was to cut prison governors' staffing costs.