It was a perfect day at the beach: The sun was scorching down on the white sand. The steady onshore wind took the edge of the heat. The breeze rippled the teal ocean and topped the waves with white patches of surf. Sunshades, towels and beachgoers in their colourful, skimpy outfits tinged the wide stretch of sand. A steady murmur of the waves crashing on the beach, the people’s voices and music from smartphone speakers an...