This is a fantastic idea for retrospective infectious disease contact tracking. I hope this concept is picked up by WHO/government or at least put on a local trial.
Why don't phones already keep a local log of recent Bluetooth device IDs?
Why don't phones already keep a local log of recent Bluetooth device IDs?
Because embedded hardware like phones usually only persistently store the information for which an actual use case exists. "recent BT device IDs" amounts to quite a bit of information (that is occasionally pretty useless in the case of unknown devices) and would require frequent scanning when you are on the move with little practical purpose outside the tracking space. There's enough approaches to create these profiles from the IT security and ad space but I consider myself lucky in living in a jurisdiction where such tracking is likely considered illegal.