Although this poster might look as if its letting you know this is an ok area for checking booty calls from exes in front of your girlfriend, it’s really a warning against taking upskirt photos on Japanese public transportation.

In an increased effort to combat the harassment on women on the Japanese metro, iPhone 3G’s in Japan have a special added feature:

The camera always makes a conspicuous “shutter” sound when a picture is taken, even when the phone is set to “silent” mode.

The loud shutter sound is supposed to deter voyeurs from taking sneaky pictures up women’s’ skirts — or down their tops.

In Japan, upskirt and downblouse shots have become increasingly popular with the advent of high-resolution camera phones.

As a result, all cell phones sold in Japan make a conspicuous shutter sound, or say the word “cheese” when a snap is taken, according to Nobuyuki Hayashi, a tech reporter based in Tokyo. On almost all new cell phones, the camera shutter sound can not be muted, Hayashi says.

Terribly annoying when taking pictures at communions, theme parks, the mall, historic sites, or in the privacy of your own dungeon, but quite useful when deterring pervs on your commute. Hentai!

Now, if only phones in New York would send an electric shock directly to a man’s taint whenever he utters “chula” or “mamasita” in a stranger’s ear.

To Prevent Upskirts, Japanese iPhone 3G Always Alerts When Taking Photos [Cult of Mac]