South Korea, China, and Singapore have successfully used digital contact tracing to
control the spread of COVID-19, often putting public interest above individuals’ right
to privacy. Despite initial enthusiasm for this approach in the USA, Israel, and Europe,
privacy concerns and technical issues inhibited uptake of digital contact tracing,
and recent attempts to stem the first wave of SARS-COV-2 infections failed.

Source: www.thelancet.com