Sentencing Watkins, Mr Justice Royce described him as a 'sexual predator' and told him he was a danger to the public.
He said that Watkins told the author of a pre-sentence report of a 'desire to shock' and the report concluded Watkins presented a 'high risk.'
Detective Daniel Minto from South Wales Police was one of the officers who trawled through the vast amount of data found on Ian Watkins' computer. He said the sheer scale of the operation was the biggest challenge and described Watkins' as a 'technically switched-on individual.'
Jan Pickles from the NSPCC says the children involved in Watkins' offences faced "a lifetime of damage." She says the case is not about "celebrity" but about children.
Trial judge Mr Justice Royce told Ian Watkins during sentencing that the case was one of the most horrific he has seen in court. Condemning the lead singer's sex crimes, some too distressing to report, in the strongest possible terms, he said Watkins was a dangerous sexual predator.
"Those who have appeared in these courts over many years see a large number of horrific cases. This case, however, breaks new ground. You, Watkins, achieved fame and success as the lead singer of Lostprophets.
"You had many fawning fans. That gave you power. You knew you could use that power to induce young female fans to help satisfy your insatiable lust and take part in the sexual abuse of their own children.
"Away from the highlights of your public performances lay a dark and sinister side. I am satisfied that you are a deeply corrupting influence, you are highly manipulative, you are a sexual predator, you are dangerous."
Nicola Bowes, forensic psychologist at Cardiff University, told ITV News that these types of offences are rare, but have a 'devastating' for the families involved.
Suzanne Thomas, senior Crown Prosecutor at CPS Wales, speaking after the sentencing Watkins was the "ringleader" of a "terrible conspiracy" to commit "appalling crimes of abuse against young and defenceless victims."
The detective leading the investigation into Ian Watkins says the evidence was the 'most disturbing' he has seen in his career.
Police are urging anyone affected by the case to contact them on 02920 634184 or the NSPCC on 0808 800 5000.
Ian Watkins has been sentenced to a total of 29 years in prison, not 35 as initially reported. He must serve two thirds of his sentence before he is eligible for parole. Once released from prison, Watkins will serve a further six years on licence.
In his summing up comments ahead of sentencing, the judge said Ian Watkins and his co-defendants committed "sickening and incomprehensible" crimes.
The details of the offences, many of which have been two graphic to report, were condemned in the strongest possible terms by the judge, as he reflected on how the singer used his power and celebrity to "partake in insatiable lust."