For these apps to be effective, experts estimated they required adoption by approximately of the population. In reality, adoption rates in many countries plateaued well below 30%, with privacy concerns cited as the primary barrier. The Core Privacy Fears
The Trust Gap: How Privacy Fears Stalled Digital Contact Tracing Privacy Concerns Hindering Digital Contact Tracing
Users expressed deep distrust toward private tech companies, fearing their sensitive health and location data would be sold or shared for commercial purposes. For these apps to be effective, experts estimated
Privacy and Security in Digital Health Contact-Tracing - MDPI For these apps to be effective
The very nature of a notification—telling you that you were near someone infected—can inadvertently reveal that person's identity in small social or professional circles.