Officials swooped on Ty-Rae Cherry’s St Kilda home on March 31 after a tip-off from US authorities.
A social-media platform had detected the distribution of illegal images and videos and made a report to the National Centre for Missing and Exploited Children, which in turn informed New Zealand Customs.
It traced the IP address to Cherry’s house and seized six electronic items.
When the defendant was interviewed, he made immediate admissions about his crimes, saying he had been looking at the illicit material for more than a year.
Cherry said he knew it was "bad".
He had created an account on the social-media platform in December 9 last year, the court heard.
Within a week he was involved in the illicit trade of depraved files.
During a 50-minute window in the early hours of December 15, he sent 18 publications to another user via private message.
One of them featured a girl as young as 3 years old being abused while tied to a table with rope. The video lasted nearly two minutes.
Over the ensuing weeks, court documents detailed how Cherry continued his offending on an almost daily basis.
On January 15, he sent nine files to another like-minded user and engaged in a chat.
The user said he had a wife and children and discussed abusing his children while they were on sleeping pills.
Cherry commented he would do the same to "my own girls if I have them".
In total, during the five-week period from December 15, he distributed 137 images and videos and was found in possession of 506.
The children involved were between the ages of 3 and 12, the court heard.
"One can only imagine the physical and emotional harm that must result from such abuse of children," said Judge David Robinson.
When Cherry was interviewed before sentencing, he said he started watching anime (Japanese animation) at 15, moving on to explicit versions and then to child pornography.
He admitted to a "fixation and fascination" with the illicit videos but denied he felt any sexual arousal while viewing them. He said, however, that it was unlikely he would have stopped offending had he not been apprehended.
A psychologist said Cherry’s social isolation as a teen had resulted in him spending increasing amounts of time online.
"He’s got on the web, his life is on the web and he’s been subject to negative influences that are there," said counsel Len Andersen KC.
He said Cherry was motivated to attend therapy, was assessed as a low risk of "contact offending" and he argued home detention was the appropriate outcome.
Judge Robinson, though, could not reach a sentence of less then two years where that could be considered.
Cherry was convicted of 13 counts of distributing an objectionable publication and two of possessing such publications.
He was jailed for three years two months, which meant he would be automatically added to the Child Sex Offender Register.
