Back in May 2016, US government attorneys obtained a warrant demanding that everyone in a Lancaster, California, building attempt to unlock an encrypted mobile phone with their fingerprint. According to Forbes , which first reported the case, the warrant was executed.
Now, a federal judge in Illinois has denied a similar request, saying that the warrant application does not establish sufficient probable cause to force anyone at the premises to give up their fingerprint, and that it raises serious concerns under the Fifth Amendment's protection against compelled self-incrimination. As Orin Kerr has pointed out in The Washington Post, by responding to an order by picking the finger that was selected to unlock the phone, the person is actually admitting that it is their phone.
The new document signals a developing trend in the drafting of so-called mass fingerprint warrants.
"Essentially, the government seeks an order from this Court that would allow agents executing this warrant to force 'persons at the Subject Premises' to apply their thumbprints and fingerprints to any Apple electronic device recovered at the premises," the opinion and order signed by United States Magistrate Judge M. David Weisman from the Northern District of Illinois, Eastern Division, reads.
Riana Pfefferkorn, a cryptography fellow at Stanford Center for Internet and Society, shared the document on Twitter on Wednesday.
"The request is neither limited to a particular person nor a particular device," the order continues. According to the order, the case revolves around a perhaps still developing child pornography investigation.
Rather stunningly, the warrant application does not actually specify what specific devices located at the premises are to be searched; it only says "it is likely" Apple devices will be found at the residence, according to the order.
That doesn't mean that these sort of warrants may always fail, writes Judge Weisman, such as in cases where an individual is shown to have a more firm connection to criminal conduct.
"We simply are not there yet," Judge Weisman writes.
Andrew Crocker, staff attorney at the Electronic Frontier Foundation, told Motherboard in a Twitter message, "I'm glad to see the Illinois applying extra scrutiny to this kind of request. Despite the government's claims that this sort of warrant is routine, it raises a host of constitutional issues, as the court noted."
The Department of Justice did not immediately respond to a request for comment.
Update: This story has been updated to include comment from the Electronic Frontier Foundation.