In Riley v. California, the Supreme Court unanimously held that police need a warrant to search through cell phones, even during otherwise lawful arrests. But if you hand over your unlocked phone to a police officer and offer to show them something, “it becomes this complicated factual question about what consent you’ve granted for a search and what the limits of that are,” Brett Max Kaufman, a senior staff attorney in the ACLU’s Center for Democracy, told The Verge. “There have been cases where people give consent to do one thing, the cops then take the whole phone, copy the whole phone, find other evidence on the phone, and the legal question that comes up in court is: did that violate the scope of consent?”

If police do have a warrant to search your phone, numerous courts have said they can require you to provide biometric login access via your face or finger. (It’s still an unsettled legal question since other courts have ruled they can’t.) The Fifth Amendment typically protects giving up passcodes as a form of self-incrimination, but logging in with biometrics often isn’t considered protected “testimonial” evidence. In the words of one federal appeals court decision, it requires “no cognitive exertion, placing it firmly in the same category as a blood draw or fingerprint taken at booking.”

it's unbelievable that there is a distinction in US caselaw between giving up your biometrics and giving up your password, and your essentially unchangeable biometrics are somehow the one you're probably obliged to give to the cops if they ask. just an incredibly goofy system