Catching A Pervert: Sexual Assault For Sale

Women who are groped on trains in East Asia face the further threat of their assault being filmed and uploaded for sale online. In a year-long investigation, the BBC World Service's investigative unit, BBC Eye, has gone undercover to unmask the men cashing in on sexual violence.

Cast: Zhuoran Tang, Noctis Zang, Lupus Fu, Zhaoyin Feng