Having had time to think about it I probably wouldn’t have told the family. Even if photographs were being taken, (not someone just being bored at airport and doing some
spur of the moment perving) they wouldn’t have been salacious, and it’s highly unlikely that they’d be so widly circulated as to cause concern to the girl or her family.
I agree the distress would be caused by “knowing”.
I’d have probably let the perp know with a stern look and some finger wagging. Not exactly saving the world but enough to put a stop to what was happening.
On another note it’s a shame Edukator has been treated poorly by some forum members. He at no point condoned or supported the perp’s activities. In my view he just tried to give some insight into French law and legal culture. Something I found interesting and informative.