The Supreme Court’s 5-4 decision in Carpenter v. United States marks a significant gain for privacy advocates as well as a monumental shift in how both the Fourth Amendment and the “third-party” doctrine are interpreted.

Among those who made the decision possible is Nathan Wessler, the American Civil Liberties Union attorney who argued on behalf of Timothy Carpenter before the court. Legaltech News recently caught up with Wessler to get his thoughts on the case’s significance, the justices’ views on privacy, and what privacy questions remain to be answered.