The Supreme Court should recognize and give teeth to the critical, privacy-protecting limitations Congress placed on wiretaps, EFF told the court in an amicus brief we filed with the National Association of Criminal Defense Lawyers.

When law enforcement officials wiretap someone’s cell phone, the law doesn’t allow them to tap any phone they want anywhere in the country. The Wiretap Act (also known as “Title III” because it comes from Title III of the 1968 Omnibus Crime Control and Safe Street Act) permits wiretapping, but only under the narrowest of circumstances and subject to restrictive requirements carefully drawn to protect extremely sensitive privacy interests.

One of those requirements is that judges can only authorize wiretap orders for interceptions that occur within their districts. In other words, either the cell phone, the place of interception, or both, must be in the judge’s district for a wiretap to be valid under Title III. So an order issued by a judge whose district is comprised of a single state, say Kansas, can only authorize the interception of calls on a phone in Kansas or from an interception point in Kansas. In Dahda. v. U.S., a federal judge in Kansas issued a wiretap order allowing the defendants’ phones to be tapped anywhere in the country. This clearly runs counter to Title III’s geographic limitations.

There are strong policy reasons supporting these territorial limitations. A wiretap is a massive invasion of privacy because it allows the government to listen—in real-time—on our phone, text, and email conversations. Law enforcement can access any other…