A prolific paedophile who blackmailed online victims into depraved acts was a "VIP member" of internet child sex abuse forums, a court has heard.
Dr Matthew Falder was a member of several "virtual communities" of abusers, and in one such forum on the so-called dark web had a "membership rank level of 'Rapist'", prosecutors said.
Falder forced one victim to film herself licking toilet seats, a used tampon and eating dog food, and set up secret cameras in bathrooms to record women and girls naked.
Another was blackmailed into eating his faeces and drinking urine, while the 29-year-old also encouraged the rape of a boy, aged two, by his own father.
The Cambridge graduate has admitted 137 offences related to 46 victims whom he blackmailed, manipulated and deceived.
Falder then shared his material with "hundreds of thousands" of other paedophiles on secret internet forums, prosecutor Ruona Iguyovwe told Birmingham Crown Court on Friday.
She added that despite Falder being caught, the victims were left feeling the material now existed "in perpetuity" online, adding that the "virtual abuse" continued.
A British undercover National Crime Agency (NCA) officer helped build the case against "predatory serial offender" Falder, posing as a member of one of these online groups in order to snare the depraved abuser.
Falder lived "a double life", by day a respectable geophysics lecturer at Birmingham University, but online - hiding behind different personas - enjoying "special membership" in the paedophile underworld.
He posted material of vile torture and sexual abuse under online handles such as "Evilmind", covering his tracks by using secure browser Tor and anonymous email addresses.
In one such post, Falder, under the name "666devil", posted paedophile material of "an instructional video on how to sexually abuse young children without being detected".
Ms Iguyovwe added: "The images of many historical abuse victims were distributed on a very large scale on those websites, the memberships of which run into the many hundreds of thousands."
The sites were associated with paedophiles and those interested in "hurtcore" - material which depicts rape and 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".
Ms Iguyovwe, prosecuting, said he had enticed his own victims "to produce increasingly severe self-generated indecent images of themselves, the focus of these images being to humiliate and degrade the victims".
Further grim details of Falder's offending, including sharing and distribution of vile and depraved abuse material, were described on the third day of his sentencing hearing.
Falder was only snared after an NCA-led investigation, with help from GCHQ, the United States Homeland Security Investigations, and law enforcement in Israel, Slovenia, Australia and New Zealand.
Charting the "exceptional gravity of the case", prosecutors invited the judge to consider a discretionary life sentence for "highly manipulative" Falder, of Edgbaston, Birmingham.
The hearing continues.