A depraved paedophile who used online blackmail to target a string of vulnerable victims, including a girl who was ordered to eat dog food, is due to be sentenced on Monday.
Cambridge graduate Matthew Falder has admitted 137 offences relating to 46 complainants after being caught by an international inquiry led by the National Crime Agency.
The 29-year-old was arrested in June last year after three traumatised victims, who were tricked into sending him humiliating images, attempted to end their own lives.
A previous hearing at Birmingham Crown Court was told Falder coerced male and female victims into producing "increasingly severe self-generated indecent images of themselves, the focus of these images being to humiliate and degrade".
Opening the facts of the case against Falder, prosecutor Ruona Iguyovwe told the earlier hearing many of the images were then distributed on so-called "hurtcore" websites showing material depicting sexual and physical abuse.
Falder, who treated victims both as sex objects and as objects of derision, posted on one forum "100 things we want to see at least once".
In remarks in that post, he suggested "a young girl being used as a dartboard", production of a video depicting a child's bones being "slowly and deliberately broken", and the abuse of "a paralysed child".
It also emerged during the earlier hearing Falder initially duped victims into providing images by posing as a female artist who wanted to turn them into life drawings.
The operation to catch Falder, who used specialist software to hide his online accounts, was aided by GCHQ, the United States Homeland Security department and law enforcement bodies in Israel, Slovenia, Australia and New Zealand.
Falder, of Harborne Park Road, Birmingham, has been told he may face a life sentence for the offences, committed over an eight-year period.
The former post-doctoral researcher in geophysics at the University of Birmingham is due to be sentenced by Judge Philip Parker QC at the city's Crown Court.