Records of journeys made by people using smart cards that allow 17 million Britons to travel by underground, bus and train with a single swipe at the ticket barrier are among a welter of private information held by the state to which MI5 and police counter-terrorism officers want access in order to help identify patterns of suspicious behaviour.
One solution being debated in Whitehall is an unprecedented unlocking of data held by public bodies, such as the Oyster card records maintained by Transport for London and smart cards soon to be introduced in other cities in the UK, for use in the war against terror. The Office of the Information Commissioner, the watchdog governing data privacy, confirmed last night that it had discussed the issue with government but declined to give details, citing issues of national security.
Now that the Oyster card can be hacked, we learn that MI5 thinks the system is good enough to assist in preventing terrorism.
The two situations donâ€™t quite sync.