Notes on Exposure Notifications

Literally just notes, from an essay I never managed to write.

Assumed Audience: People willing to think about the intersection of tech and public health (and willing to consider the public good, not just)

Epistemic Status: Literally just an outline I wrote when I thought I would have time to turn them into an essay for Mere Orthodoxy, back when Apple and Google’s exposure notification systems were first proposed.

A very long time ago, relatively early in the pandemic, Google and Apple put their heads together and came up with a system to provide privacy-protecting notifications of exposure to COVID-19. I thought then, and think now, that this was a good investment. Sadly, it has mostly failed to be effective in the U.S. because it was not rolled out in a remotely consistent way, and because most people who get a positive COVID test do not report that with their phone. But it was still a good idea!

This evening, I came across the outline I wrote up about it all those many months ago, and figured it might be interesting to see where my head was at the time. What follows is just that outline, with not alterations whatsoever.


  • Alternative approaches

    • Approaches actively in use elsewhere
      • Taiwan
      • South Korea
      • China
    • Proposed, as in France
    • Don’t do any of this
  • Concerns

    • Liberty and privacy
    • Possibility of later abuse by govt.
      • Repurposing for contact with undesirables
    • Security: can it be compromised?
      • Risk of leaking who has the virus
      • Death threats to public figures who’ve had it
      • Location data vulnerable to stalkers etc.
    • Efficacy
      • Usually in tension with privacy
      • This design mitigates that… if and only if people enable it, because it’s opt-in
      • Not as effective as a tracing system, but also has none of its downsides
    • Ethics: is it good or right, regardless?
  • Mitigation of risks via technical implementation details: point-by-point handling for each of those concerns

  • Benefits

    • Supporting public health efforts by providing people with info to act appropriately
      • Lyman Stone’s post
    • Encouraging continued social distancing in a reopened economy
    • a Christian frame with love of neighbor in mind
      • Protecting each other is good
      • Enabling reopening of economy is good
      • Safeguarding liberty and protecting privacy from leaks is good
        • Risk of abuse from misguided conspiracy theorists is real
      • How tech forms us, especially in its ubiquity (?)
  • Net: turn it on!