> https://stallman.org/rms-lifestyle.html
"Cell phones are tracking and surveillance devices. They all enable the phone system to record where the user goes, and many (perhaps all) can be remotely converted into listening devices."
This morning, I went in with my old Thinkpad on which I have replaced Xubuntu with Slackware/MLED including a complete reformat and encryption of the SSD. The wifi recognised the machine and greeted me by name. I can only assume that the server is recording the MAC addresses of devices that use the system. That is just about the only thing left that it could be reading.
I believe WiFi routers have options for white-listing devices by MAC address. Probably being done automatically in your building.
It would appear to be: http://www.zdziarski.com/blog/?p=2738
I encountered this problem in Dublin airport a few years ago, before they switched to a different wifi provider.
The authentication code to join the wifi network would be sent by SMS. Which seems clever, until you realise that many people transiting Dublin won't have international roaming ( I didn't ) so can't receive the SMS.
When toll-free phone number services started providing number identification to the service in the 1980s, American Express had their system look up the customer's record from the phone number, and their operators started greeting customers by name. Some customers saw this as "creepy", and American Express stopped such greetings, although the customer's record was still looked up.
Today, everybody has caller ID and name lookup.