Exclusive: sometimes there is a difference between fiction and reality.
Steve Hewlett is presenting a report at the moment on BBC Radio 4, Privacy Under Pressure. Three episodes, Episode 2 was on Monday 22 July 2013, last episode next Monday, don't miss it, 9 a.m.
Everyone remembers Minority Report, the Tom Cruise film where people are identified by the patterns of their irises. As they walk around the shopping mall, personally tailored advertisements invite them to enjoy special offers in the shop they're just passing.
Politicians may believe that this technology already works and is available today. It isn't. Senior civil servants and journalists may believe it but they're wrong, too.
What is available, is a technology claiming to recognise your face – not your irises. Steve Hewlett interviewed James Orwell, a face recognition expert at Kingston University.
How well does face recognition work in a shopping mall today? Hundreds of times better than it used to, said Dr Orwell, but still not well enough. If we had one million people's faces on file and we searched for a match using an image caught by an overhead CCTV today, we'd probably be able to narrow it down to the nearest 5 percent.
That is, we'd know that the person who's just been filmed isn't among these 950,000, he or she is one of the remaining 50,000 people on file. Probably.
Useless. And here he is, saying it.
Minority Report-style biometrics may work in Hollywood. They don't work in Kingston.