what is "Wangiri" fraud?
Wangiri is a kind of fraud done via telephones. People receive an incoming call that only rings once. But the number of the calling remains on a phone's record screen, often inducing users to return the call. Then, users are directed to a taped message of a seductive female voice simulating sex or information about adult entertainment. Wangiri, which is actually a combination of the English word, "one" pronounced as "wan" in Japanese and the Japanese word, "kiru", meaning to "cut off." Recently, it has vexed not only individual telephone users, but also caused mass telephone disruptions.
Comments
Some measures suggested by DoCoMo to crub Wangiri fraud
http://www.theregister.co.uk/2002/08/30/mobile_phone_scam_kills_curious/
http://www.theregister.co.uk/2002/08/30/mobile_phone_scam_kills_curious/