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Will London Monetize Wifi Tracking Data From Its Tube Passengers? (gizmodo.co.uk)

Posted by EditorDavid on from the down-the-Tube dept.

New questions are arising about how much privacy you'll have on London's underground trains. "For a month at the end of last year, Wi-fi signals were used to track passenger journeys across the network," writes Gizmodo. "The idea is that as we travel across the Tube network, Wi-fi beacons in stations would detect the unique ID -- the MAC address -- of our phones, tablets and other devices -- even if we're not connected to the Tube's wifi network." The only way to opt-out is to turn off your phone's Wi-Fi. An anonymous reader writes: London is struggling with the transport network capacity so the ability to learn commuters' travel patterns is compelling... Now it emerged that TfL, the operator of London Subway system, is planning to use the system to monetize passengers' data. TfL is also not ruling out sharing the data with third-parties in future.

More information shows that the privacy protection could not be as good as TfL maintains, with reversible hashing and options of giving data to law enforcement. A privacy engineering expert points out additional issues in pseudonymisation scheme and communication inconsistencies. Final deployment has been initially scheduled to start in end of 2017.
"Once the tools are in place, there will inevitably be a temptation to make use of them," warns Engadget, raising the possibility of the data's use for advertising -- or even the availability to law enforcement of location data for every passenger.

4 of 90 comments (clear)

  1. Overcomplicating matters by andrewbaldwin · · Score: 5, Insightful

    I can sympathise with TfL's stated aims - knowing how many people go from place A to place B via route C at certain times of day is useful and can be socially beneficial if it helps train scheduling.

    But this can be done in a simpler way (albeit not in real time - but is that really necessary?).

    Many years ago I recall using the metro and local trains in Copenhagen when they were doing a survey. When you entered the station they gave you a paper slip with the station name and timeslot written on it; when you reached your end destination there was a bin to drop the paper slip into. That's it from the passenger viewpoint - minimal inconvenience and no linking to you as a person (and you could even opt out by keeping the paper slip if you were so minded).

    I'm guessing that at the end of the day they collected the slips at each station and could work out just how many people went on each journey within hour long blocks.

      I do recall thinking that a bar code or QR block would simplify the counting process.

    But that's not cool enough - it's too simple for today's management to consider (and it cannot be subverted or surveilled).

    Slightly off topic - doesn't everyone turn off the phone wifi & bluetooth when not in use? -- doing so seems [in my experience -YMMV] to extend the time between charges by quite a useful margin.

    1. Re:Overcomplicating matters by Anonymous Coward · · Score: 1, Insightful

      they have all of the information on how people are moving across the whole transportation network already - via the Oyster (contactless transport ) cards. So that's a BS aim of tracking.

    2. Re:Overcomplicating matters by oobayly · · Score: 5, Insightful

      The reason they did this was to track people's routes through the system - Oyster will only give the end points, not where they changed stations. The Gizmodo article explains that, if you bothered to read it...

      The Register did an article on this a few weeks ago and mentions that TFL did a good job anonymising the data:

      Fortunately, TfL did it right: they used ICO guidelines to protect users' privacy by grabbing and tracking MAC addresses and then depersonalized them using a salt which then discarded at the end of each day. That in effect makes it impossible to know what the original MAC address was.

  2. Sigh by ledow · · Score: 3, Insightful

    Paranoia much?

    Pretty much if you're on a train (especially a Tube train) then you bought a ticket from A to B or - in London - you bought an Oyster card which records your every journey as you have to tap-in and tap-out.

    This is quite normal for any train/subway system. What information do you think they are going to glean from Wifi that they can't glean in this manner about travel patterns? Only what you give them, and only of little use (does it REALLY matter that the guy going from Embankment to Mile End did a DNS lookup for slashdot.org, and how on earth would you ever properly correlate that if he only quickly checks a website at stations he never alights at, and then turns Wifi off?).

    This is the "machine learning" rubbish all over again. Masses of data, lots of processing, no more insight into anything useful over and above monitoring ticket sales which you have to do anyway.