Drones are governed by regulations from the Civil Aviation Authority that require operators to avoid endangering people or property. Drones must remain within visual line of sight, not fly near congested areas or large gatherings of people, and not fly at night without permission. Stricter rules apply if the drone has a camera. While many regulations exist, policing violations is difficult as drones can operate anonymously and footage of incidents like floods may have been recorded in violation of regulations. There are calls for better controls on drone use for surveillance as existing laws were not designed for this new technology.