Judges imposed lengthy sentences to the monsters who manipulated their victims by grooming and subjecting them to degrading, prolonged assaults.

Others downloaded thousands of disturbing child abuse material files, with detectives uncovering offenders' sick, illegal behaviour.

Ex-Scouts leader Darren Vuolanne was found guilty of sexually abusing four young girls in the Illawarra between 1996 and 2001, following a week-long trial.

As Judge Megan Latham sentenced Vuolanne to 16 years' jail, a supporter of one of the victims exclaimed "every dog has it's day, you piece of sh--" from the back of the room.

Vuolanne was found guilty of 11 charges related to his offending against the girls when they were aged seven to 15.

One of the victims told the jury Vuolanne repeatedly molested her as a child, saying he raped her "15 to 20 times".

South-western Sydney man Evangelos Nussis, who would make a six-hour round trip on public transport to rape a 15-year-old girl, was jailed for five years and six months.

Communication between Nussis and the girl began on the online game Fortnite in March 2020, when he was 27 and she was 14.

He pleaded guilty to seven counts of sexual intercourse with a child and was sentenced in May 2023.

The disturbing crimes took place in a secluded spot at Wollongong's City Beach and once in a room at City Beach Hotel.

The victim still grapples with an "overwhelming sense of shame" as a result of Nussis' crimes, Judge Alistar Abadee said before imposing a non-parole period of three years.

Albion Park predator Alex McPhie, who masqueraded as a 13-year-old boy to manipulate three young girls into sending him explicit pictures, was jailed for six years.

He forced one of the girls to undress in a traumatic 36-minute Snapchat call, telling her he would email her school with her nude images if she didn't comply with his demands.

After officers raided McPhie's address, child abuse material - including the photos and videos sent by his victims - were located on two of his iPhones.

Judge Siobhan Hubert fixed a non-parole period of four years, noting McPhie's crimes had a degree of cruelty as he knew his victims were distressed by his coercion.

Former child soldier and aspiring musician Miguel Guevara was sentenced to 11 years' jail for sexually abusing four girls between the ages of nine and 15.

One of his victims told the Mercury that her family was torn apart by Guevara's offending, but urged other child abuse victims to come forward to seek "closure".

Guevara was found guilty in August of 13 charges, including sexual intercourse with a child between 10 and 14 and aggravated indecent assault.

His offending spanned across seven years while he was in a position of trust.

Mount Pleasant man Adam Orvad learnt his fate in August after being caught with more than 90,000 files of "callous" child abuse material.

Orvad came under the notice of detectives in 2021 who were notified he uploaded child abuse material online.

Investigators uncovered the tens of thousands of files after raiding Orvad's home in 2022.

"It's also a callous crime because ... the offender is reminded of that exploitation and abuse and the degradation that causes," Judge Andrew Haesler said.

Orvad was jailed for three years and four months.

Illawarra father-of-three Bradley Abbott dodged time behind bars after undercover police caught him grooming someone he believed to be a 14-year-old girl.

He asked the girl if she wanted to meet up and suggested they "Could grab a coffee, or we could muck around in the car ... kiss or have sex and even just feel."

Abbott was placed on a Child Prohibition Order.

Thirroul pensioner Kenneth MacDonald was found guilty in December to 11 historic child abuse charges, with a supporter of one of the victims clapping as he was taken into custody.

MacDonald's opportunistic and brazen offending against two young girls happened frequently between 1980 to 1989. His crimes ranged from persistent sexual touching to digital penetration.

MacDonald will be sentenced on February 23.

Helensburgh bakery delivery driver Mark Williscroft admitted to a raft of sickening crimes including filming young girls in his neighbourhood and owning thousands of child abuse material files.

His twisted behaviour was discovered by police who seized several devices with 100GB of child abuse material on it - including videos depicting sadism, bestiality and infants.

Williscroft also groomed a girl into sex acts after he drugged her with cannabis and alcohol. He will learn his fate in the New Year.