Right. They've done the exact same tracing for years as part of the "Find my phone" feature, but now it becomes problematic when it's used to mitigate a pandemic outbreak? That makes zero sense.
1. the telcos have months - if not years - of LAC update data stored for every phone. They know where you sleep, who visits and where you work and shop;
2. they analyse the CDR for every call/SMS send and received (caller and receiving party cells) [look at your spam SMS with a jaundiced eye];
3. they 'ping' thousands of phones* daily to trilaterate the location to metres (and/or A-GPS, TDOA, etc.)
4. they analyse the voice and data handover records.
* The preferred way to do this with a veneer of deniability is for the authorities to add in a few phones into the known associates list of phones to be monitored in an otherwise legitimate drug or terrorist warrant.
They judges will never know (and certainly don't ask).
In fact pretty sure Apple has already implemented this functionality for their upcoming Apple Tags product. They have a patent on it and it works very similar to GACT i.e. by anonymously recording Bluetooth identifiers.
I'm not ready to risk giving up more privacy to "mitigate a pandemic outbreak".
I believe there are other ways to fight viruses, we (the world) should invest massively in biological R&D to better understand, protect, control and heal our body rather than track people. Tracking people is a low-level solution that misses the bigger picture.
Maybe this will be possible in 50 or 200 years, but the world we currently live in is not ready to both track people and respect basic human rights, in my opinion.
By the way : same argument is valid for nuclear weapons. Why don't we accept that all countries get nuclear weapons? Because it would be dangerous in the wrong hands.
