Put your thumbs where we can see them: German court backs forced phone unlocks

Your secrets behind biometric scanners are not as secure as you’d assume. Police are allowed to use force to unlock phones and other devices using fingerprint scanners or facial recognition, a German court rules.

A man in Germany was suspected of distributing child pornography. He refused to unlock a phone during a house search. Then, he also resisted a policewoman who tried to forcibly unlock his phone using his finger. Eventually, he was pinned to the ground and lost the thumb war, the German publication Heise.de reports.

“The police officer grabbed the defendant's arm, whereupon the defendant tried to free himself from the grip by thrashing around several times and turning away. Because the defendant continued to resist despite repeated requests, he eventually had to be brought to the ground and restrained. The cell phone was then unlocked by placing the defendant’s finger on the fingerprint sensor,” the court document translation reads.

The man was fined 300 euros ($313) for resisting the officers. Instead of paying the fine, he appealed and lost in the Higher Regional Court of Bremen. The man will bear the costs of the proceedings.

The court ruled that forceful unlocking of the phone can be justified under German criminal law.

“A milder, equally suitable measure was not available for this purpose due to the difficulties of unlocking a cell phone in any other way,” the court said.

The court explains that placing a finger on a fingerprint sensor is a similar measure to taking a fingerprint. The same applies to unlocking phones by facial recognition or iris scan, as it is similar to taking photographs of the suspects.

“This is a less intrusive measure since the recording of fingerprints allows this data to be stored and processed by comparing it with any other traces, whereas placing a finger on a fingerprint sensor on a mobile phone is a measurement for one-time use and not permanently stored by the investigating authorities,” the German court said.

The judge recognized the privacy rights at stake but determined that unlocking the phone was a justified and proportionate measure.

According to Heise.de, legal experts are still divided on the issue. The court recognized that the subsequent data use after the forced phone unlocks would need to follow separate stricter legal requirements, which were not the focus of this particular case.