Funny story that is just happening in Barcelona this season.
Local police is chasing anyone in the beaches nearby Barcelona Int. Airport.
The reason: Kites do appear on air control radar, like small little points moving up and down around.
It drove air controller completely crazy to see all those UFOs moving around with no visual contact at all.
This area used to be a kitesurfer paradise. It took 1 year to the airport to realize what was happening down there.
Now as soon as a kite appears, airport notifies the police and police chases the kitesurfer away.
So be aware that if you want to play little alien flying 4 lines UFOs in some airport neighboorhood, you're likely to see the police attacking back to prevent the new generation of space invasion.
Enjoy,
Yannick