Japan reports big rise in voyeurism as large number of people using "silent app" for smartphones are now indulging in clicking illicit photographs without people's consent.
According to a report in Mercury News, 1,741 incidents were reported last year, which was an increase of 60 per cent on the figure five years ago.
One of the 'silent camera' applications deliberately conceals what the user is doing by putting an innocent-looking email or text message on screen while he or she clicks.
There are loads of silent camera applications already available on Android Market and iTunes store and on Android particularly, there are several that appear to market themselves as being for stealthy photography, the Daily Mail reported.
"The latest applications include 'upgraded versions' that enable people to silently take photos while an email or website is displayed on the phone's screen to provide cover for the surreptitious picture-taking," said the report.
Japanese academics have called for regulation of silent photography applications claiming that they are being used for crimes.