"Maybe the first time you know you are pregnant is when a targeted piece of advertising comes through on your computer screen offering you some baby clothes because somehow the smart toilet, or some other aspect of your environment, leaked that information," he said.
Already we live in a world surrounded by sensors and recording devices, said Professor Sadler, director of the Trusted Systems Lab at Hewlett Packard. Current uses include CCTV, wildlife monitoring, mobile phone cameras and GPS devices. A 2002 study calculated there were around 4.2 million CCTV cameras in the UK, one for every 14 people. Professor Sadler said: "The average Londoner may be viewed as many as 300 times a day."
The growth in the number of devices would continue to grow, he predicted. "If you go forward 50 years, you are probably talking about one million forms of sensors per person in the UK," he said. This was a conservative estimate, he said. "More aggressive" calculations suggest there could be 20m sensors per person. Already some researchers at Microsoft, Hewlett Packard and MIT have developed devices that record a person's every move. Research like this, as well as advances in sensor technology and manufacturing techniques would see a continued "slow and incremental, year-on-year" growth in the number of devices that surround and monitor people, he said. This would result in a world where "everything we want monitored can be monitored," he said.
A lot of the applications would be "innocent and harmless", he said. We imagine by 2057 our motorways, rivers and coastal defences, farms, businesses, homes and neighbourhoods and bodies will all be highly instrumented," he said. But he said there would be potential to misuse the networks and the data they collect. "We will hit some of these scenarios when people suddenly think, 'Oh, I didn't really intend to go there'," he said. "I'm sure there will be a lot of after the event working out what we do about some of the more invasive uses of the technology."
As a result, he said, people needed to make decisions now about the future use if the technology. "We have some real choices that we can make over the next few years about how much we benefit from all this information... or how much it presents some sort of dark future for us."