The makers of the film Dallas Buyers Club are hunting Australians who downloaded or shared the movie illegally.
They've filed a discovery order in the Federal Court in a bid to get names and contact details from five Aussie telcos: iiNet, Internode, Dodo, Amnet and Adam Internet.
Discovery orders are used in cases where the identity of the person or company targeted for legal action is unknown.
iiNet has opposed the application, citing "serious concerns" that the film's makers will look to intimidate subscribers.
"We are concerned that our customers will be unfairly targeted to settle claims out of court using a practice called `speculative invoicing'," said Steve Dalby, iiNet's chief regulatory officer.
That strategy involves sending intimidating letters to alleged offenders threatening legal action and seeking large sums of money.
It's a tactic copyright holders have used in other countries to clamp down on file-sharing via websites such as BitTorrent.
The application comes two years after iiNet won a landmark High Court case against a group of Hollywood movie studios which argued the telco was responsible for the downloading habits of users.
In a unanimous decision, the court held that iiNet could not be found liable because it did not control the sites used by customers.
It also comes as the federal government considers a range of proposals to curb illegal downloading by Australians.
One key proposal would compel ISPs to block infringing websites.
Another would compel telcos to curb illegal downloads by making it easier for rights holders to take the companies to court.
Mr Dalby says a date for a hearing is likely to be set for early 2015.