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Police can't force you to unlock your phone with your fingerprint or face data

OnePlus 6T in-screen fingerprint reader
OnePlus 6T in-screen fingerprint reader (Image credit: Android Central)

A new ruling by the U.S. District Court for the Northern District of California prohibits police from forcing people to unlock a mobile phone with their face, iris, or fingerprint data. The ruling was delivered in response to a search warrant request that sought biometric access to unlock all devices at a residence in Oakland. Judge Kandis Westmore denied the request, stating that biometric features were equal to a password and that they also enjoyed the same protections:

The court finds that the government's request runs afoul of the Fourth and Fifth Amendments, and the search warrant application must be denied. Today's mobile phones are not comparable to other storage equipment, be it physical or digital, and are entitled to greater privacy protection.

The Fourth Amendment states that have people have the right to be secure in their houses against unreasonable searches and seizures, while the Fifth Amendment protects against self-incrimination. From the ruling:

If a person cannot be compelled to provide a passcode because it is a testimonial communication, a person cannot be compelled to provide one's finger, thumb, iris, face, or other biometric feature to unlock that same device.The undersigned finds that a biometric feature is analogous to the 20 nonverbal, physiological responses elicited during a polygraph test, which are used to determine guilt or innocence, and are considered testimonial.

As noted by Forbes, the ruling is a landmark decision for privacy advocates, but it remains to be seen if the District Court's verdict will be upheld in the higher courts.

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Harish Jonnalagadda
Harish Jonnalagadda

Harish Jonnalagadda is a Senior Editor covering Asia at Android Central. He leads the site's coverage of Chinese phone manufacturers, and writes about the semiconductor industry, storage servers, and audio products. Contact him on Twitter at @chunkynerd.

  • They can't *legally* force you. That's quite a distinction. And that's probably only until it gets overturned by whichever court is one higher than District. Is it, state?
  • Circuit Court I believe
  • For better or for worse (depending on your point of view), the judge is a magistrate judge, not an actual District Court Judge. So, this decision can be reviewed still by the District Court without an appeal to the Circuit Court (the Ninth Circuit). However, an appeal isn't likely what would be done by the state anyway because they're trying to get a warrant for something on phones NOW, not days, weeks or months down the road. If a decision like this is made against the defendant in this or another case and the defendant is convicted, that person can then appeal up through the courts using this court's reasoning and arguments and higher court rulings will have broader effects. I get what the judge is saying, but I think that other judges will have a tougher time saying that someone's face and fingerprint are "testimonial" and comparable to indicators in a polygraph such as pulse, blood pressure and galvanic skin response. Our faces and fingerprints are so universally shared that we have very little expectation of privacy in them from a legal point of view.
  • You don't know our police!
  • This is the first time I've heard of a search warrant being requested for biometric data to unlock phones. I've just heard of police compelling suspects to apply their finger or iris in moment, and that their actions were deemed legal by a judge later on. I can't decide how higher courts will deal with this. Law is squirrelly sometimes.
  • Yeah, but the can still make u use your backup pin/pattern! Instant loophole :::(
  • Lot's of things to talk about. I believe the term "houses" should be replaced with your person, personal property while home or away from home should be amended into the current amendment. I'm all for law enforcement, but people do have rights and it isn't my job to help prosecute "me" for things that may or may not be illegal. In our local school district, they is wording in the code of coduct that states a designated school employee (Administartor, Resource Officer or Police) can search your child for "cause" including asking them to empty a backpack, purse, pockets, locker, search vehicle on school premesis, and require a student to turn over their cellphone or other electronic devices and unlock them. This can be done without contacting the parent. I have a PIN and pattern to unlock my phone. as does all my family members. I am interested to see if those to the Supreme Court and how the ruling affects our local school code of conduct.
  • I believe that if the police had their way we would have no rights at all and thats sad. I understand that they have a job to do but their power must be limited strictly in order to prevent great abuse.
  • While I get what you're saying, in the real world, as a law-abiding citizen, my risk of being abused by criminals is far greater than my risk of being abused by the police. Finding the balance between personal privacy freedom and protection from criminals who think only of themselves is always going to be difficult.
  • It's easy for you to say that you're more likely to be abused by criminals because you're a law-abiding citizen however, in some areas including where I live... I am more likely to be harassed by police than I am by criminals! I have been stopped and accused of Grand Theft Auto for sitting in my car because I had an African-American individual with me in the car. I am a law-abiding citizen and I have been molested by police who groped my breasts while giving me a "stop-and-frisk" several years ago,, I can go on with more examples but as a white woman I am harassed by police on a relatively regular basis. I know my husband who is African American gets it 100 times worse than me! In fact, several weeks ago I was driving in my Mercedes Benz 450 when a policeman accused me of not being allowed to drive in the state seriously! This stuff happens a lot more frequently than most people realize. When I was accused of not being allowed to drive in Washington state because my car is licensed in the state of Oregon (Portland Oregon) I was just dropping my daughter off for school and was flagged down by a policeman. They need to stop being allowed to have all the rights to harass law-abiding citizens! They already go to far. Am anyone who has been harassed by police, your obviously one of the lucky ones.