The issue before the Court in Navarette v. California, No. 12-9490 was:
Whether the Fourth Amendment requires an officer who receives an anonymous
tip regarding a drunken or reckless driver to corroborate dangerous driving
before stopping the vehicle.

In a 5-4 decision, with Justice Thomas writing for the majority, the Court
held that “the stop complied with the Fourth Amendment because, under a
totality of the circumstances, the officer had reasonable suspicion that
the driver was intoxicated.”
Justice Scalia, writing for the dissent (joined by
Justices Ginsburg, Sotomayor and Kagan), noted that the majority opinion
“purports to adhere to our prior cases” and “does not explicitly adopt… a
departure from our normal Fourth Amendment requirement that anonymous tips
must be corroborated.”  But, Justice Scalia, warns:  “Be not deceived.”
“The Court’s opinion serves up a freedom-destroying cocktail.”  He
explains:  “Law enforcement agencies follow closely our judgments on
matters such as this, and they will identify at once our new rule: So long
as the caller identifies where the car is, anonymous claims of a single
instance of possibly careless or reckless driving, called in to 911, will
support a traffic stop. This is not my concept, and I am sure would not be
the Framers’, of a people secure from unreasonable searches and seizures.