A lot of people don't like modern technology, they fear the unknown. All that couple probably knows is that Fox News runs a lot of negative reports on 'drones' and they think you are up to no good. I have a summer seasonal site my 5th wheel sits and I occasionally get someone who mentions the privacy thing. I offer to let them see the monitor or show them a video of me flying in that area to assure them you cannot see who people are should they be in view. Most seem to 'get it' after talking with me and viewing the video. There's always one in every crowd unfortunately.
Society is a mess

Everyone is concerned about privacy and yet they have FB, Twitter, Instagram and trying to get randoms to follow.
Nudist at public beaches are concerned about their privacy. WTFLOL!!!
Parents are concerned about kids privacy when their teens are sending nudes to each other at school and randoms online..
Ever since 9-11, the norm is too assume the worst. Fear mongering

Just off tangent...
This is how messed up we are.. A parent missed placed her 2 (maybe 3) year old and wasn't aware until she was running towards the road. I picked her up before she became roadkill. The problem is that I'm not too sure on how I picked her up - you don't think in these matters. The mother came running and was infuriated. I didn't know better as she was screaming in Chinese. I thought she was angry at her girl. I passed the girl back to her smiling thinking I deserved a medal. She continued blasting as I walked off to catch up with my mates. A bystander saw it all and said if you knew what she said, you should have just let the child get hit. "What the hell you doing with my kid!!! You're a disgusting pervert touching my kid and I hope you will never have kids!!!", he translated. What the mother didn't realise was that she didn't see me save her child and because I don't have kids, I possibly held her "inappropriately"). The bystander said he will explain to her what had just happened. My mates said to grab the kid's arm next time.