You might be interested to know that the Managing Director of the Fukuoka Stock Exchange was arrested yesterday[1][2] on allegations that he took upskirt shots of schoolgirls. He was caught because his tablet's camera emitted the mandatory shutter sound.
Laws like this serve primarily to deter casual criminals and catch patently stupid criminals which are the vast majority of cases. In this case it took a presumable sexual predator off the streets, which is a great application of the law.