A British scientist pleaded guilty Monday to 137 criminal offences involving online abuse, including encouraging the rape of a four-year-old boy, the National Crime Agency said in a statement.
Matthew Falder, 28, who dubbed himself "666devil" and "evilmind" online, blackmailed many of his 50 victims into sending "severe abuse images" of themselves.
Falder, whose victims ranged from young children to people in their 30s, would pose as a woman and get his victims to send naked images. He would then manipulate them into sending increasingly depraved abuse images.
"The purpose was to humiliate and degrade the victims," the NCA said.
Falder, a geophysicist, admitted the charges at a court hearing in Birmingham, central England, making him one of Britain's most prolific sex offenders.
"In 30 years of law enforcement I have never come across such horrifying offending where the offender's sole aim was to cause such pain and distress," said NCA senior investigating officer Matt Sutton said.
"It has been an extremely complex investigation into a prolific online predator, who over several years believed he could evade law enforcement to sexually and sadistically exploit vulnerable victims."
Falder is a graduate of Cambridge University and was a postdoctoral researcher at Birmingham University.