Unlike virus-tracing apps that continuously track users' whereabouts, the Apple and Google software relies on Bluetooth signals, which can estimate the distance between smartphones without needing to know people's locations
Sarah Cavey in Denver, May 21, 2021. Cavey downloaded an app from Google and Apple meant to help contact tracing for the coronavirus. But after testing positive for the virus in February, she was unable to get the special verification code she needed from the state to warn others, she said, even after calling Colorado’s health department three times.
Image: Rachel Woolf/The New York Times
Sarah Cavey, a real estate agent in Denver, was thrilled last fall when Colorado introduced an app to warn people of possible coronavirus exposures.
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