Kurtis Whaley, 24, targeted boys as young as eight by posing as a 16-year-old Perth girl and persuading them to transmit sexually explicit images or videos of themselves over Instagram and Snapchat.

The material he received was covertly saved and used in a "premeditated system of intimidation" to entice his victims to share more, NSW District Court Judge Ian Bourke said on Tuesday.

"(He) very clearly and very cleverly tricked victims into supplying pictures of their faces (which he used) to enslave them ... to satisfy his perverted sexual desires," the judge said.

When demands for additional videos and images weren't met, Whaley shared what he had with those close to the victims including their underage friends and siblings.

That was "nothing short of cruel and merciless," Judge Bourke said, jailing him until mid-2028 for the "persistent and frequently cruel" offending.

With time served, Whaley will be eligible for parole in mid-2025.

The offending began in 2014 on Skype and video chat site Omegle before Whaley turned to Facebook, Snapchat and Instagram, where he was able to exploit the victims' close relationships.

Boys tricked into complying with Whaley's demands came from areas including Victoria, NSW and Queensland, as well as New Zealand and the United States.

One victim involved in a car crash had his mercy plea ignored while another victim was warned by Whaley to stop delaying as "it'll only make things worse".

A friend of one victim who received an explicit image from Whaley cautioned it was illegal.

"It's blackmail and you're spreading child pornography," the victim's friend said.

But Whaley was undeterred.

"Mate, I've been doing this long enough haha. What can the police do? Honestly," he said.

"If they could do something there wouldn't be crimes like this. But there is. And that's because police don't have tools or power to catch people like me."

Federal police, tipped off by the father of a 13-year-old victim, identified the IP address linked to Whaley's Instagram account and arrested him at Sydney Airport in February 2019.

Child abuse material was found on the phone and tablet he was carrying and on five hard drives at his Manly Vale home

Judge Bourke said authorities were yet to identify some of the victims portrayed in the 700 images and videos Whaley had solicited during his four-and-a-half-year scheme.

The hard drives also contained 255 images and video of child abuse material Whaley had sourced from elsewhere. Those victims were aged between four and 15 years old.

His sentence was cut by 25 per cent for his early guilty pleas to 54 charges, including 29 counts of using a carriage service to solicit child pornography and five counts of using such a service to transmit child pornography.

The UK-born man was working full-time and studying optical dispensing at the time of his arrest.

Educated in Adelaide before residing in Melbourne and Sydney, Whaley told the court he was ashamed and didn't want his victims to think it was their fault.

"It is my fault and I have made them feel this way," he said.

Judge Bourke acknowledged that was a positive sign but noted the offending remained unexplained.

Australian Associated Press