2 Channel no Noroi: Gekijôban (2011)

The Shark Island Incident was thought to be a joke, with 2chan users discussing a fictitious incident in a setting where they were not allowed to talk about it with other 2chan users. However, the threads were posted as usual, "I want to know the truth of the case," and the participants began to talk about the details of the Shark Island Incident, saying, "I have no choice but to tell you the truth then....

Unfortunately the movie 2 Channel no Noroi: Gekijôban is not yet available on HBO Max.