A man said to be among the UK's worst paedophiles was a "VIP member" of internet child sex abuse forums, a court has heard.
Details of Cambridge graduate Dr Matthew Falder's 137 offences against 46 victims were listed at a sentencing hearing at Birmingham Crown Court.
He posted messages on a child's bones being "slowly and deliberately broken", and abusing "a paralysed child".
Prosecutors said he had a "membership rank level of 'Rapist'" on one forum.