Shit its a duck - shoot it! The owner cannot have been far away and obviously within visual distance to control it if it was actually following you. If it was on a GPS course out of the owners line of sight of you and it then it would not follow you. So some smart arse was stalking you! Next time follow it - the batteries cannot last more than half hour and it will have an average of 1k range depending on type. It has a camera so was taking a vid of you and its owner was probably watching you on an Ipad or similar.
If it was following me on my own property then it would have been shot down - no second thoughts about that…invasion of privacy.