I have pointed out the weakness of the correlation between viral transmission vectors and BTLE radio signals these apps are relying on a few times before here on HN. I've pointed to the failure of deployment % reaching anywhere near the required density (and we are talking order of magnitude off here, not 'just missing a few %') where citizens had free choice. We've already seen many authorities requesting 'more control' and lambasting Google/Apple for being too restrictive.

But on HN, any criticism of this tech is met with a swift unsubstantiated down-vote.