Perhaps next time be nicer. I mean, I imagine this being a mess, each country having it's own rules - maybe it's legal but regulated - does size matter? - d

Perhaps next time be nicer. I mean, I imagine this being a mess, each country having it's own rules - maybe it's legal but regulated - does size matter? - does it matter when you cross a border? - do you have to announce? - does it matter how high you fly it? - are the International norms? - are there regulatory bodies?