Generally I agree that location tracking is already relatively widely done, and the Apple/ Google protocol makes reasonable efforts to preserve privacy. I do s

Generally I agree that location tracking is already relatively widely done, and the Apple/ Google protocol makes reasonable efforts to preserve privacy. I do share some caution, however -- tracing 'personal contacts' by BTLE is likely much more personally specific, and hence significantly more intrusive, than just location. If such mechanisms became more generally available they would likely become used as part of the machinery of repression in states such as China. Or everywhere (depending on our future). Location is fairly imprecise as to social contact, but I guess the concern would be that this will be accurate enough to track dissenters, find their contacts, and accuse/ imprison you.