"There is no “one size fits all” approach to digital contact tracing technologies (DCTT). Technology design should not be static, but it should be capable of evolving depending upon local conditions, new evidence, and changing preferences and priorities. Technology companies alone should not control the terms, conditions, or capabilities of DCTT, nor should they presume to know what is acceptable to members of the public. DCTT should be designed to have a base set of features that protect privacy, with layers of additional capabilities that users may choose to activate. An initial default should be that user location data are not shared, but users should be provided with easy mechanisms and prompts to allow for opting-in to this capability, with encouragement to the public if it is shown to be critical to achieving public health goals. Data collected through DCTT should be made available to public health professionals and to researchers in de-identified form to support population-level epidemiologic analyses." (Summary, p.2)