[criddell]

Don't Android and iOS randomize the MAC addr these days? Are they investing in something that's going to have a very short life?

[tinus_hn]

At least on iOS it is only randomized while scanning, not while connecting to networks you have used before. Which is kind of obvious because otherwise your login won't persist.

[benbristow]

You need to login to the TFL WiFi using your Virgin Media or supported phone network's login, so they can identify you by that instead.

[uniformlyrandom]

Yes, but this is easy to opt-out from. Naturally, this is not what they are doing:

> At the end of 2016, TfL ran a pilot which tracked the Wi-Fi signals from 5.6 million phones as people moved around the London Underground, even if they weren't connected to a Wi-Fi network.

[criddell]

Is that just if you want signal under ground, or is having WiFi turned on a requirement for riding Tfl?

[Angostura]

If you want to use their wifi :)

[akvadrako]

Another way to think about it is as taking advantage of a window of opportunity to gather the data before it disappears.