A British academic who went by the online aliases of “evilmind” and “666devil” was sentenced to 32 years in prison Monday for posing as a depressed female artist to coerce people as young as teens to send him naked and partially-clothed images of themselves.

Matthew Falder, a 29-year-old geophysicist at Birmingham University, found his victims on advertising websites and then blackmailed them into sending him even more humiliating photos by threatening to deliver the original racy snaps to their family, friends and employers, Reuters reported.

“The effects on the girls, women and men were devastating. The damage is ongoing for these individuals,” Judge Philip Parker said during sentencing at Birmingham Crown Court. “It will never end. Time and again people begged you to stop. Time and again you ramped up the pressure.”

Using 70 different aliases, Falder would distribute the images on hidden Internet forums devoted to talk on rape, murder, pedophilia, degradation and other grisly subjects, according to Reuters.

Britain’s National Crime Agency (NCA) said Falder came into contact with more than 300 people across the world. Forty-five victims were represented in the 137 offenses he pleaded guilty to in October, including encouraging the rape of a 4-year-old, voyeurism and making indecent images of children.