I have mixed feelings about the iPhone 5S’s fingerprint reader. On the one hand I believe it would encourage users to enable the security features on their phones. On the other hand it makes things easier for law enforcement because forcing somebody’s finger onto a reader is much easier than coercing their password out of them. As it turns out there may be additional legal issues regarding Apple’s fingerprint reader:
Courts have given mixed messages about whether Americans are protected from being forced to divulge passwords or decrypt information for law enforcement officials. Civil liberties advocates argue defendants shouldn’t have to unlock their own computers for the cops. The logic: Under the Fifth Amendment, Police can’t force you to self-incriminate by testifying, or divulging something in your mind.
It’s unclear if that same protection applies if the password is your fingerprint.
“A fingerprint is entitled to less constitutional protection than a password known in your mind,” said Hanni Fakhoury, a staff attorney at the Electronic Frontier Foundation in San Francisco. “If police arrest you and ask you for a password, you could refuse and they’d be hard pressed to force you to divulge the password.”
Of course, police already collect fingerprints after booking a suspect. And the Supreme Court has also held that police don’t need a search warrant to collect fingerprints.
The combination of being able to collect fingerprints without a search warrant and the east of which a person’s finger can be forced onto a scanner creates a dangerous legal environment. It’s not stretch of the imagination to think of a situation where a police officer forces a suspects finger onto their phone’s scanner, finds incriminating evidence, and makes an arrest based on that evidence. During the court battle the office would argue that he is allowed to collect fingerprints without a search warrant, which is what he did.