Only yesterday I was reading a Reddit thread where someone new to Japan asked whether to inform the police of the apparently violent arguments his neighbours were having and the responses varied from "don't bother, the police won't care" to "make a noise complaint, at least the police will be interested". That's the least scary anecdote I have.

⁎ Probably not about Japan specifically :)

As far as I remember Jphone, the company first heavily advertising camera phones, forced the shutter on its own to preemptively clear itself from any potential issue.

Every phone carrier from there had the choice to forgo the mandatory shutter sound but risk backlash if anything were to happen, as Jphone set a precedent. And they choose the safety move.

When the iPhone came, it would have just been a marketing quagmire to go with a mutable sound.