How does contact tracing work? Bluetooth proximity.
Who makes the applications? Cell phone operating system vendors: Google, Apple, (application vendors?).
Who has evaluated the sufficiency of privacy in contact tracing? Are data de-identified? Is it geographically abstracted to a the postal forwarding service area (FSA)? What would be shared with public health and are there any ethical implications in the use of this Real World Evidence (RWE)? Is the data reliable or evidence grade?