Fourth Amendment Victory: Michigan Supreme Court Reins in Digital Device Fishing Expeditions

EFF legal intern Noam Shemtov was the principal author of this post.

When police have a warrant to search a phone, should they be able to see everything on the phone—from family photos to communications with your doctor to everywhere you’ve been since you first started using the phone—in other words, data that is in no way connected to the crime they’re investigating? The Michigan Supreme Court just ruled no. 

In People v. Carson, the court held that to satisfy the Fourth Amendment, warrants authorizing searches of cell phones and other digital devices must contain express limitations on the data police can review, restricting searches to data that they can establish is clearly connected to the crime.

The realities of modern cell phones call for a strict application of rules governing the scope of warrants.

EFF, along with ACLU National and the ACLU of Michigan, filed an amicus brief in Carson, expressly calling on the court to limit the scope of cell phone search warrants. We explained that the realities of modern cell phones call for a strict application of rules governing the scope of warrants. Without clear limits, warrants would  become de facto licenses to look at everything on the device, a great universe of information that amounts to “the sum of an individual’s private life.” 

The Carson case shows just how broad many cell phone search warrants can be. Defendant Michael Carson was suspected of stealing money from a neighbor’s safe. The warrant to search his phone allowed the police to access:

Any and all data including, text messages, text/picture messages, pictures and videos, address book, any data on the SIM card if applicable, and all records or documents which were created, modified, or stored in electronic or magnetic form and, any data, image, or information.

There were no temporal or subject matter limitations. Consequently, investigators obtained over 1,000 pages of information from Mr. Carson’s phone, the vast majority of which did not have anything to do with the crime under investigation.

The Michigan Supreme Court held that this extremely broad search warrant was “constitutionally intolerable” and violated the particularity requirement of the Fourth Amendment. 

The Fourth Amendment requires that warrants “particularly describ[e] the place to be searched, and the persons or things to be seized.” This is intended to limit authorization to search to the specific areas and things for which there is probable cause to search and to prevent police from conducting “wide-ranging exploratory searches.” 

Cell phones hold vast and varied information, including our most intimate data.

Across two opinions, a four-Justice majority joined a growing national consensus of courts recognizing that, given the immense and ever-growing storage capacity of cell phones, warrants must spell out up-front limitations on the information the government may review, including the dates and data categories that constrain investigators’ authority to search. And magistrates reviewing warrants must ensure the information provided by police in the warrant affidavit properly supports a tailored search.

This ruling is good news for digital privacy. Cell phones hold vast and varied information, including our most intimate data—“privacies of life” like our personal messages, location histories, and medical and financial information. The U.S. Supreme Court has recognized as much, saying that application of Fourth Amendment principles to searches of cell phones must respond to cell phones’ unique characteristics, including the weighty privacy interests in our digital data. 

We applaud the Michigan Supreme Court’s recognition that unfettered cell phone searches pose serious risks to privacy. We hope that courts around the country will follow its lead in concluding that the particularity rule applies with special force to such searches and requires clear limitations on the data the government may access.