In all the debate about David Blunkett's proposals to introduce ID cards, another affront to civil liberties seems to have slipped through the campaigners' nets. This is the Oyster card used on London's buses and the Underground. Press it down on a yellow "reader" as you enter the station, and the gates automatically open. (Unless you swipe it too quickly, or the machine is broken - then it doesn't work at all.)
I tried to add some money to my Oyster card the other day - to "top it up", in Oyster parlance - and saw on the computer screen an entire record of my journeys in the past month. Anyone peering over my shoulder would have seen exactly where I embark on my journey, and when. They would have been able to see that I was late for work (St James's Park, District Line) on a couple of days, not, as I had claimed, because I had been stuck on a delayed train, but because I hadn't actually entered the station (Highbury and Islington, Victoria Line) near my home until well after I should have done. And had I reason (oh, I don't know why - to cover up a bank robbery, for example, or to deny adultery) to claim that I was in one part of London at a particular time, London Underground would have the wherewithal to prove that my Oyster card had been used on the other side of the capital at that moment.
Which is fair enough, really, if you want to prevent false alibis for bank robberies, but perhaps not if the information is made available to anyone trying to prove that I wasn't, say, admiring art at Tate Modern (Southwark, Jubilee Line), but shopping instead for a new wardrobe (Oxford Street, Central Line).
I worry, too, that Oyster cards could be cancelled if a person falls out of favour with either the state or any of the London Underground staff. With normal travel cards phased out and Oyster cards the only way to get about, a person could be frozen out of the entire transport system.