If you had the joy of travelling on the London Underground between the 21st of November and the 19th of December, the more eagle-eyed commuters among you would have spotted the privacy information notices that had sprung up in most tube stations.
Unbeknownst to most, TFL has been working to capture anonymised data on the movement of wifi connected devices within its network, and therefore the movements of their human carriers.
The resulting analysis is fascinating and demonstrates the power massive data collection combined with some very smart human analysis. The result will be less congested trains for Londoners (thanks to better informed infrastructure decisions) and better advertising revenue across the network. Revenue that may well contribute towards the proposed 'fare freeze'.
TfL even checked if this data was accurate, by matching it up with actual train timetables, and was able to demonstrate how on one journey southbound down the Victoria Line they were able match the wifi data of one passenger and figure out which specific train they were travelling on. The upshot of this is fairly obvious. As TfL says itself “By using Wi-Fi data, merged with aggregated Oyster and Contactless ticketing data we would have a far richer data source to ensure optimal and evidence based decision making for a wide range of planning decisions.”.