Within an hour an Invercargill teen had been named as the girl in the video and posters were threatening violence against her.
While Netsafe agreed the actions captured in the footage was horrific, chief executive Martin Cocker believed sharing the video had put the girl's life in danger.
"People shouldn't be exposed to that kind of content. The actions shown in the video should never have been undertaken either but the video shouldn't have been shared," he said.
He noted the numerous threats of violence against the girl named in comments, paired with numerous posts sharing the address and phone number of the girl people believed was involved. In combination, he said this was "concerning".
He also said this was a "fairly predictable" outcome from sharing that kind of content.
"If you put a video like that out there, you know that people are going to be motivated to find the person involved and get justice."
While Cocker said it was understandable that Paw Justice was outraged at what the video showed, he suggested the best response was to report it.
"If you come across that kind of content you can report it to police or to Netsafe.
"You cross a line when you identify anyone involved in something like that, or make threats towards them."
SPCA Southland operations manager Richard Hay said the SPCA's Invercargill branch was aware of the incident and who was behind the abuse.
"We are having discussions with police as well as the people involved," he said.
Hay said both organisations were involved in an investigation, which was in its "early stages".
In its original Facebook post Paw Justice said the video "sickens and saddens us at the same time, because this is reality in New Zealand".
"This terrible act of cruelty and senseless death of a young kitten is what we have to fight against! We can't even begin understand why this little soul was stoned to death," the post said.
"What the hell is happening with our youth if they can do this and laugh, and in front of at least one young child."
Paw Justice had initially asked people to "please stand with us, identify them", however a second post this morning asked people not to name and shame anybody.
"Please do not post addresses or make calls for vigilante justice. We cannot allow this for many reasons, including legal and privacy reasons," the post read.
"We understand the anger, trust us, we do. But we have a job to do, and we have to do it properly."
