In the case of Florida v. J.L., the U.S Supreme Court ruled unanimously that an anonymous tip lacking corroborative details was insufficient grounds for a stop-and-frisk. The case involved a juvenile, identified as J.L., who was searched by Miami-Dade police after they received an anonymous tip that he had a gun. Although officers found a firearm on him, no other criminal activity was observed prior to the search and seizure. The court held that this violated his Fourth Amendment rights against unreasonable searches and seizures because there were no specific or articulable facts to justify reasonable suspicion for the search beyond just carrying out law enforcement duties based on an unverified tip-off.

In the dissenting opinion for Florida v. J.L., Justice Ginsburg, joined by Justice Breyer, argued that an anonymous tip should be enough to justify a stop and frisk if it provides sufficiently detailed predictive information. They contended that such tips could demonstrate sufficient indicia of reliability to provide reasonable suspicion for a search. The majority's decision requiring additional evidence beyond an anonymous tip would undermine law enforcement efforts and potentially endanger public safety. They also disagreed with the majority's assertion that there was no way to test the credibility of anonymous informants; they believed officers could assess reliability based on factors like voice stress or background noise indicating proximity to alleged criminal activity.