Stalking was the act of following someone in a threatening manner without their consent.
After hearing Tolian Soran speak negatively of time – calling it a predator that stalked one, always killing in the end – Jean-Luc Picard discussed Soran's sentiment with William T. Riker, saying he did not share that view. (Star Trek Generations)
In 2377, Deanna Troi, surprised to meet up with Reginald Barclay at the beach, scolded him for following her on vacation, as she deemed it inappropriate for a therapist's patient to do so. (VOY: "Inside Man")