Supreme Court Justice Antonin Scalia (Luis Alvarez/Associated Press)

As reported by my colleague Robert Barnes, Justice Antonin Scalia wrote that the government needed a valid warrant before attaching a GPS device to the Jeep used by D.C. drug kingpin Antoine Jones, who was convicted in part because police tracked his movements on public roads for 28 days.

The justices, in a unanimous decision, found the action constituted a “search” as outlined in the fourth amendment protection against unreasonable searches and seizures.

Here’s the SCOTUS opinion.

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