Lucas Michael Chansler, a 26-year-old Florida man, was jailed last year on multiple charges, including production of child pornography, though the FBI said on Tuesday it has only been able to locate a third of his “sextortion” victims. These FBI videos describe how at least 250 of Chansler’s victims have yet to come forward after he tricked them into incriminating behavior on live video he later used to blackmail them, a form of sextortion.

Chansler would first pretend to be a 15-year-old boy who would try to strike up conversations with young women on the now defunct video streaming service Stickam, the FBI said. He also used other types of online networks, the FBI said in a press release.

Sometimes the victims would be at a sleepover and believed they were having a casual online conversation with a boy they likel