The US Constitution's Fifth Amendment protection against
self-incrimination does not prohibit police officers from forcing a
suspect to unlock a phone with a thumbprint scan, a federal appeals
court ruled yesterday.
...
Judges rejected his claim, holding "that the compelled use of Payne's
thumb to unlock his phone (which he had already identified for the
officers) required no cognitive exertion, placing it firmly in the same
category as a blood draw or fingerprint taken at booking
