Drones
In the UK, if you wish to operate commercially, it is regulated. Undertake some on-line learning ( principles of flight, Meteorology, Map reading ) then attend ground school for 3 days ( air law, air safety, aircraft knowledge, human factors deployment procedures in accordance with your ops manual and flight reference cards ) and then finally complete a flight assessment on type. On successful completion you can then apply to the CAA for "permission for Aerial work". You maintain a log book ( to prove currency ), keep records ( locations, times etc where you have undertaken flights ) and have an annual assessment of your flying ability and maintenance review of the drones. Does this all sound familiar?
The rules are essentially operate up to 400' and line of sight 500 metres, no closer than 50 metres to people or buildings not under your control and no overflight of crowds or built up areas without permission. Complete a sight recce, risk assessment and have a spotter with you and the camera operator. It is all pretty H&S orientated. Operating outside these parameters is on a case by case basis after applying to the CAA. Night ops can be undertaken when you have passed a suitable course.
The UAV ( unmanned aerial system ) or RPA ( remotely piloted aircraft ) are pretty sophisticated. Flight controllers for manual or autonomous flight, GPS, FPV ( first person viewing - you see what the camera sees ) and ground control stations ( flight planning via computer of course, height and speed ). Loss of signal and the drone will return to the take off point and land. Low and reducing power will result in an auto landing.
The privacy aspect is a potential issue as always but if engaged in commercial filming/photography then the company hiring your service will have that reasonably covered.
Third party liability is essential.