https://phys.org/news/2018-07-drones-dire-reputation.html

But these spectacular views have come at a price. Drones have gained a poor reputation, especially in cities. As the name suggests, drones give off a distinctive and often unpleasant humming sound that can reverberate through densely populated areas. On a more sinister note, drones can furtively peep through the windows of any residence like a mobile, motorised Big Brother. Given that drones can be flown from a great distance, it may be impossible to identify who lurks behind the lens.

Drones can be annoying and invasive, but they can also be actively dangerous. Near misses between drones and piloted aircraft more than tripled between 2015 and 2017 – usually because of lack of due care from the drone user.