In Terry v. Ohio (1968), the Supreme Court recognized the need for police-initiated confrontations with private citizens based on less than probable cause. Since Terry, however, the Court has offered little clarification of its concept of reasonableness. The Court in Adams v. Williams upheld a police officer's stop and frisk on an informant's tip, but since has refused to grant certiorari on the issue of whether an anonymous tip may furnish reasonable suspicion for stop and frisk. New York's court of appeals has sanctioned Terry confrontations based solely on anonymous tips. While New York codified Terry in its Criminal Procedure Law, the court of appeals formulated a more expansive approach to stop and frisk in People v. De Bour. In People v. Howard, the court of appeals apparently rejected the right of police to pursue a suspect without probable cause. An examination of Howard and well-reasoned lower court decisions that have not followed Howard support the view that a police officer should be able to pursue a fleeing suspect upon reasonable suspicion. The court of appeals has taken a more liberal approach to the use of anonymous tips. On one hand, it has sanctioned the use of sufficiently detailed anonymous tips as the sole predicate for a stop and frisk, but also has held that generalized anonymous tips concerning armed persons generate no more than the common law right of inquiry. In cases involving anonymous tips of dangerous criminal activity, police should have an automatic right to stop a suspect who reasonably can be identified from the description given and if the tip states a suspect is armed, a qualified automatic right to frisk should arise. The article includes 164 footnotes.