Newly recognized Fourth Amendment rights in mobile phone location data highlighted the U.S. Supreme Court’s criminal docket for the October 2017 term.

Chief Justice John G. Roberts Jr. once again led the court’s march toward greater search and seizure protections in the digital age.

His landmark 5-4 decision for the court in Carpenter v. United States held that gathering the data from wireless carriers usually requires probable cause warrants. In doing so he upended the logic previously used by lower...