Call local law enforcement; stalking and unauthorized surveillance are illegal in many jurisdictions.
Keep the drone in sight from a distance to see where it lands or who is operating the remote.
For legitimate pilots looking to avoid being perceived as a "stalker": SDTeen Drone Stalker
Stalkers are attracted to metal; they will pick up your camera drones and carry them to their nests. Protection: Avoid parking drones in the Kelp Forest or Safe Shallows .
If you feel a drone is being used for stalking or harassment, follow these safety and legal steps: Protection: Avoid parking drones in the Kelp Forest
Maintain a respectful distance from private residences and windows.
Retrieve drones immediately after use to prevent them from being moved to a distant nest. For follow-me features, use drones like the HoverAir
For follow-me features, use drones like the HoverAir X1 or DJI Mini series which have advanced obstacle avoidance.