Interesting question. I think they’ll definitely be used by commercial companies. Map makers can use them to get cheap high quality “satellite” photos of areas (1). The police are already using them as mobile CCTV cameras (2). People could use them for market research if they flew one over a busy town centre and were able to do some simple tracking. It would probably start with examining the flow of people like watching the flow of a river and then it may reach the point where you can track an individual person shopping all day. It might be time to read 1984.