Wednesday, May 1, 2024

Compelled to Unlock With Fingerprint

Jon Brodkin:

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. The ruling does not apply to all cases in which biometrics are used to unlock an electronic device but is a significant decision in an unsettled area of the law.


Payne’s Fifth Amendment claim “rests entirely on whether the use of his thumb implicitly related certain facts to officers such that he can avail himself of the privilege against self-incrimination,” the ruling said. 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.”

Joe Lancaster (via Hacker News):

From a practical standpoint, this is chilling. First of all, the Supreme Court ruled in 2016 that police needed a warrant before drawing a suspect’s blood.


But forcibly gaining access to someone’s phone provides more than just their identity—it’s a window into their entire lives. Even cursory access to someone’s phone can turn up travel history, banking information, and call and text logs—a treasure trove of potentially incriminating information, all of which would otherwise require a warrant.

When they drafted the Fourth Amendment, the Founders drew on the history of “writs of assistance,” general warrants used by British authorities in the American colonies that allowed government agents to enter homes at will and look for anything disallowed. As a result, the Fourth Amendment requires search warrants based on probable cause and signed by a judge.

John Gruber:

People who don’t use Face/Touch ID are surely tempted to use a short easily-entered passcode for convenience, and anyone who disables Face/Touch ID while using a nontrivial passphrase is encountering a huge inconvenience every single time they unlock their phone. There’s no good reason to put yourself through that.

My advice is to internalize the shortcut to hard-lock an iPhone, which temporarily disables Face/Touch ID and requires the passcode to unlock: squeeze the side button and either of the volume buttons for a second or so.


Those concerned with civil liberties should presume, though, that the same court would rule similarly regarding cops unlocking a device by waving it in front of the suspect’s face. But with “Require Attention for Face ID” — which is on by default — Face ID won’t work if you keep your eyes closed, and I don’t think a court would allow police to force your eyes open. The trick to worry about is the police handing you back your phone, under the pretense that you can use it to make a call or something, and then yanking it from your hands after you unlock it.

John C. Welch:

“Ha, I locked my phone, you can’t make me put in my pin!”

<cops all turn off their body cams and draw their sticks>


3 Comments RSS · Twitter · Mastodon

Ah, John Welch, nothing like a light joke about police violence. I wonder what George Floyd's pin was?

Old Unix Geek

Typing in a pin is hardly a major inconvenience... I find Gruber's advice bizarre.

Also: John Welch is still alive? Who knew.

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