Both Dmitri and Ian sent me a link to a a feature from the BBC's site on how the police are increasingly using Oystercards to follow people's movements: "In January, police requested journey information 61 times, compared with just seven times in the whole of 2004. The Metropolitan Police said it was a 'straightforward investigative tool' used on a case-by-case basis."
Last month I blogged how Oystercards could be used to track down partners who were being unfaithful and claiming they were somewhere where they weren't, but this use of Oystercard is either a good way of finding criminals or an infringement of people's privacy depending on what side of the fence you sit:
Charles Monheim, from Transport for London, told the BBC London reporter: "Big Brother is not watching you. We collect journey data so we can provide customer service and answer customer queries. A by-product of that is that the data is on record if the police seek records in individual cases, but we only provide that data in response to a written request from the police that is then reviewed on a case by case basis".
Whereas Heather Brooke, from Privacy International, said: "I think it's outrageous. Londoners are already the most watched people on earth.
"If the police can't conduct effective investigations with a CCTV camera on every corner, then that's really indicative of a more serious problem with police investigations."