Here's the sequence of events: 1. You're walking, with your phone in your pocket. 2. Suddenly, a cop accosts you. You don't have time to react. 3. They detai

Here's the sequence of events: 1. You're walking, with your phone in your pocket. 2. Suddenly, a cop accosts you. You don't have time to react. 3. They detain and restrain you (with handcuffs or otherwise) 4. They pat you down and find your phone 5. They take your hand and place it on the fingerprint sensor. Ignoring #2 (and the terrible language you used), I don't see how my scenario is significantly more or less likely than yours.