  Data collection and processing via digital public health technologies are
being promoted worldwide by governments and private companies as strategic
remedies for mitigating the COVID-19 pandemic and loosening lockdown measures.
However, the ethical and legal boundaries of deploying digital tools for
disease surveillance and control purposes are unclear, and a rapidly evolving
debate has emerged globally around the promises and risks of mobilizing digital
tools for public health. To help scientists and policymakers navigate
technological and ethical uncertainty, we present a typology of the primary
digital public health applications currently in use. Namely: proximity and
contact tracing, symptom monitoring, quarantine control, and flow modeling. For
each, we discuss context-specific risks, cross-sectional issues, and ethical
concerns. Finally, in recognition of the need for practical guidance, we
propose a navigation aid for policymakers made up of ten steps for the ethical
use of digital public health tools.
