As a tourist, I had to provide a phone number of a contact person in Taiwan upon my arrival. They call the number and confirm it works before you even leave the CDC checkpoint at the airport. You also self report your health condition. I then stood in line for 4 hours to get a special taxi to my place of quarantine. Taking public transport is forbidden. Before finally getting into the taxi, I was sprayed all over (including the bottom of my shoes) with with I presume was disinfectant.
I was later requested to add a police officer on the social media platform Line, through which I’m now asked daily how I’m feeling, and offered help if I need anything. However I don’t think they can track my position through it.
There’s a stall selling cheap SIM cards for tourists at the airport, but it’s past the CDC checkpoint, so no tourist has a local number to provide. Perhaps they should move it upstream (and just provide the cards for free), if they want this “electronic fence” to be watertight. I’m not sure but I think I could technically go wherever I pleased right now.