Www.bbc.co.uk/news/uk-england-london-48365417

Aside from the big brother concerns, I found the images from the 2016 pilot fascinating to look at. 

Having travelled via King's Cross and Waterloo many times, it's interesting to see how they map usage between the two stations. 

Amongst others, I've done the Euston walk and changed Northern Line trains at Euston and also got off at Vauxhall a couple of times, but much prefer the change at Bank.