Warner Bros, Disney and 20th Century Fox were among the companies accusing the ISP of allowing its customers to partake in illegal downloads, claims which the country's High Court have now dismissed.
iiNet was initially taken to court by 35 movie and TV companies in 2010, but the judge ruled that the network provider did not authorise any illegal downloads or have the power to prevent them. Australia's High Court backed the decision, throwing out the studios' recent appeal.
"The High Court held that the respondent, an internet service provider, had not authorised the infringement by its customers of the appellants' copyright in commercially released films and television programmes," read a court statement.
The Australian Federation Against Copyright Theft (AFACT) condemned the ruling, claiming that revisions to copyright law are required in order to stamp out piracy.
"Both judgements in this case recognise that copyright law is no longer equipped to deal with the rate of technological change we have seen since the law of authorisation was last tested," it said in a statement.
The ruling is expected to have a bearing on future copyright lawsuits in other territories.
> More tech news