The FBI is trying to identify victims of an online predator who targeted 350 minors in 26 states in a scheme to produce online pornography.
The FBI said 109 victims — all teenage girls — have been identified and the public's help is needed to find more victims of Lucas Michael Chansler.
Chansler was sentenced in August 2014 to 105 years in federal prison. Authorities said he had approximately 80,000 images and videos in his possession.
Authorities have found 135 screen names Chansler used, including on social media sites such as Myspace, Stickam and AIM, to send threatening messages to teen girls over the Internet.
Pretending to be a friend, acquaintance or admirer of the victims, he would invite them to live video chats, where he would ask them to expose themselves and record them. He threatened to expose those images online and to the girls' families and friends unless they provided more graphic images, the FBI said.
After his arrest, Chansler said he used social networking sites to meet underage girls because adult women were "too smart" to fall for his scheme, according to the agency.
Several videos seized by law enforcement show the girls crying and begging Chansler not to exploit them further.
"Sextortion is a growing threat both domestically and internationally," Assistant FBI Director Joseph S. Campbell said in a news release.
"This case serves as an example that children anywhere can be targeted for sextortion and that the FBI remains committed to stopping this cycle of victimization and holding the criminals accountable."
Anyone who believes she has been victimized or knows the identity of any victims is asked to let the FBI know.
People can fill out a questionnaire at FBI.gov/sextortion, send a confidential email to FBI. firstname.lastname@example.org, contact the local FBI field office at 423-265-3601 or call 1-800-CALL-FBI.