[mc32]

Japan requires the shutter snap sound as a way to combat a specific kind of unlawful photograph. Specifically upskirt and peephole surreptitious photographs, not to combat photographs of strangers, etc. It addresses a specific problem in their (and in others) society.

Of course that doesn't stop the harcore ones who build homemade cams into their shoes, or people sabotaging the speaker - but if stops most garden variety ones.