This is the trade-off. Your potential privacy against knowing if the t**t who pushed right by you in Asda has symptoms or is confirmed. On that level, it is a no-brainier.
On something so serious, you have to believe any data would be. Protected and not be used for any other purpose.
The data held and recorded third party devices is only your Bluetooth MAC address, and theirs on yours. No personal data need be involved - it’s just an electronic address (although some BT names might be interesting). That address alone says nothing about you, only your phone.
However - It relies on the other party (or you) confirming COVID-19 status. The t**t in Asda isn’t likely to do that.
BT is a point to point technology. There is no triangulation unlike on your phone signal, so actual position and hence distance from the BT alone cannot be determined. That’s going to prompt false positives but, BT signal strength could be used as a gating trigger. GPS only has an accuracy of 10m too so is little help in positioning. Approx position may be helpful though for tracing outside the app allowing authorities to trace more quickly without the need to question a potentially ill patient.
So, there’s a number of technology, process and behavioural issues to overcome.
Personally, the privacy issue is minor compared to those. But, there are a number of significant but not fatal weaknesses in the whole chain. That said, considering the frightening number of family and friends I’ve already lost, anything that helps reduce and stop this virus, the better.
This app however will not protect you in any way. It is to alert you of any previous contact. That you may not want to know, but, simply knowing about potential contact and infection is a massive bonus for the authorities in managing us out of this crisis.
Some countries are seeking mandatory powers, not for personal data reasons, but to determine the actual extent of infection and potential for transmission. They’re not looking to track you. This isn’t about that at all. That gives much greater insight into the potential viral load in the community and hence risk of a further bout of infections. This is important data. Something that technology can help with.
On the basis that phone providers already have access the location data for you, as does Google and Apple, that privacy issue is effectively a dead issue. If needed, the police can get access to that data. You can be certain the security agencies already have access to it. Besides, most of us freely give away location data in apps constantly.
Simple call - privacy or dead?
Anything that helps reduce the chance of the latter, directly or indirectly, the better imho.