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Google wants your phone to track your heart rate by simply looking at you
(www.androidauthority.com)
This is a most excellent place for technology news and articles.
So create the misconception the data remains local (as the processing happens locally), while incentivizing users to use face authentication (enabling the 8-second selfie cam video clip upon unlock: used for heart rate estimation through skin changes), and the EULA roofying of course serving as the "explicit consent".