Hello
About a year ago if been searching laws in the Netherlands about licences or regulations for slings and slinging.
There's nothing.
So it's free and legal...
But hey, I can be wrong and might have overlooked something. So I'm carefull anyway.
Espessialy with the Palestines on tv almost dayly, assosiations with riot and war are easily made.
I guess over there and in Israel there's polecy about slings, but not here in Holland, so I beleave.
Good luck
Sander