Ok, I missunderstood something on wikipedia so I thought of it as nothing bad^^
MMM: keep cool, I´ve just asked a tiny question
at spirit: I´ve asked a friend in japan and he said he didn´t hear about it and non of his friends neither so I think it does not really exist in japan or that is at least not popular, about it´s legally nobody was able to tell me something about it but I think (hope^^) it´s forbidden.
Edit: I´ve just read that japan is planning to ban mobile phones from schools to prevent something like this at least at the schoolyard so I think it´s forbidden anyways.
When do you think people die?
When they are shot through the heart by the bullet of a pistol?
No.
When they are ravaged by an incurable disease?
No.
When they drink a soup made from a poisonous mushroom?
No!
It's when... they are forgotten.
~Dr. Hiluluk - One Piece