They probably should have checked the term "sharking" before calling it - http://www.urbandictionary.com/define.php?term=sharking - big in Japan a few years ago.
Also, I hope offenders are treated to severe punishment or jail time in Japan (unless it's done with the woman's consent, which I doubt). I can't believe it's serious enough to merit its own term.
("Card shark" is, of course, a corruption of "card sharp", but an old and well-established one.)